WO2019004232A1

WO2019004232A1 - Radiographic image detection device and method for operating same

Info

Publication number: WO2019004232A1
Application number: PCT/JP2018/024252
Authority: WO
Inventors: 岩切　直人; 北野　浩一; 将清水川
Original assignee: 富士フイルム株式会社
Priority date: 2017-06-28
Filing date: 2018-06-26
Publication date: 2019-01-03
Also published as: JPWO2019004232A1; JP6864092B2; CN110832848B; US20200129138A1; US11064966B2; CN110832848A

Abstract

Provided is a radiographic image detection device capable of reducing the power consumed by a signal processing circuit during an emission start detection operation for detecting the start of radiation emission, and a method for operating the same. During an AED operation for detecting the start of X-ray emission, a control unit (54) of an electronic cassette (16) selectively outputs to an ADC (77) an analog voltage signal from some of the charge amps including the detection CAs (132) which are connected to a detection channel (95) of a detection pixel (90) for detecting the start of emissions and constitute some of the plurality of CAs (60) connected to a MUX (76), causes the ADC (77) to only perform AD conversion processing of the selectively outputted analog voltage signal, and reduces the pulse number NPU_A per unit of time of a clock signal which specifies the operation timing of the ADC (77) in comparison to when an image is being retrieved.

Description

Radiation image detecting apparatus and operation method thereof

The present invention relates to a radiation image detecting apparatus and an operation method thereof.

In the medical field, diagnosis based on a radiation image detected by a radiation image detection apparatus is actively performed. The radiation image detection apparatus has a sensor panel and a circuit unit. In the sensor panel, a plurality of pixels, which are irradiated from the radiation generation apparatus and sensitive to the radiation transmitted through the subject (patient), are arranged in a two-dimensional manner in a plurality of pixels that accumulate charges. A radiographic image detection device having such a sensor panel is also called a flat panel detector (FPD). The circuit section is provided with a signal processing circuit that converts the charge accumulated in the pixels of the sensor panel into a digital signal and outputs the digital signal as a radiation image.

The radiation image detection apparatus is classified into a stationary type fixed to an imaging table installed in an imaging room and a portable type in which a sensor panel and the like are accommodated in a portable case. A portable radiation image detection device is called an electronic cassette. Electronic cassettes include a wired type in which power is supplied from a commercial power supply via a cable, and a wireless type in which power is supplied from a battery mounted in a housing.

Each pixel is connected to a switching element, for example, a TFT (Thin Film Transistor), for selecting a pixel from which charge is read. In the sensor panel, gate lines for driving the TFTs in units of rows of pixels and signal lines for reading out the charge from each pixel to the signal processing circuit are provided so as to cross each other. That is, the gate lines extend in the row direction of the pixels, and are arranged at a predetermined pitch in the column direction of the pixels. On the other hand, the signal lines extend in the column direction of the pixels, and are arranged at a predetermined pitch in the row direction of the pixels.

The signal processing circuit includes a charge amplifier (hereinafter, CA (Charge Amp)), a multiplexer (hereinafter, MUX (multiplexer)), an AD converter (hereinafter, ADC (Analog-to-Digital Converter)), and the like. The CA is provided for each signal line and connected to one end of the signal line. CA outputs an analog voltage signal corresponding to the charge flowing from the pixel through the signal line. A plurality of CAs are connected to the input terminal of the MUX, and one ADC is connected to the output terminal. The MUX sequentially selects analog voltage signals from the plurality of CAs connected to the input terminal, and outputs the selected analog voltage signal to the ADC. The ADC executes an AD conversion process that converts an analog voltage signal from the MUX into a digital signal according to the voltage value.

When the radiation is irradiated, charges corresponding to the dose of the radiation reached are accumulated in each pixel. The radiation that has passed through the subject is attenuated according to the transmittance of the subject, so that charges representing image information of the subject are accumulated in each pixel. The signal processing circuit reads out the charge representing the image information of the subject from the sensor panel and converts it into a digital signal, and outputs it as a radiation image of one screen to be provided for diagnosis.

Patent Document 1 describes a radiation image detection apparatus in which a sensor panel has 2880 rows × 2304 columns of pixels, and a signal processing circuit has nine MUXs and ADCs. In Patent Document 1, when reading a radiation image of one screen from the sensor panel, the signal processing circuit performs the following image reading operation. That is, gate pulses are sequentially applied to the gate lines of 2880 rows, and the TFTs of each row are sequentially turned on one by one, and in each case, the charges of the pixels in one row in which the TFTs are turned on It flows simultaneously to the signal lines of each column. As a result, the charges of the pixels in one row are read out and accumulated in each of the CAs connected to the respective columns of the 2304th signal line. Since there are nine MUXs and ADCs, 2304/9 = 256 columns are occupied by one block composed of one MUX and one ADC. The nine blocks operate in parallel at the same timing. Each MUX sequentially selects analog voltage signals from 256 CAs connected thereto, and outputs the selected analog voltage signal to each ADC. Each ADC sequentially converts an analog voltage signal from each MUX into a digital signal and outputs it. The output of digital signals for one row corresponds to image reading for one row. When the image reading for one line is completed, the same operation is repeated and the image reading for the next line is performed. A radiation image for one screen is output by repeating such an image reading operation for one row for 2880 lines.

Moreover, the radiation image detection apparatus described in Patent Document 1 has an irradiation start detection (hereinafter, AED (Auto Exposure Detection)) function of detecting the start of irradiation of radiation using a sensor panel. Specifically, similarly to the above-described image reading operation, the operation of reading the charges of the pixels as digital signals is repeatedly performed before the start of radiation irradiation. Here, in order to detect the start of radiation irradiation, the operation of converting the charge of the pixel into a digital signal and reading it out is repeatedly performed before the start of radiation irradiation, and the radiation start of radiation is determined based on the digital signal. Hereinafter, in order to distinguish this operation from the image reading operation, it will be referred to as an AED operation.

When radiation irradiation is started, the amount of charge generated in the pixel increases compared to before the start of irradiation. In Patent Document 1, the digital signal read out in the AED operation and the irradiation start determination threshold set in advance are compared with each other in the same manner as the image reading operation, and the digital signal becomes larger than the irradiation start determination threshold. It is determined that radiation irradiation has been started. Then, when it is determined that the irradiation of radiation has been started, while the radiation is being irradiated, the pixel charge accumulation operation of accumulating charges in the pixel is performed, and then the image readout operation is performed. According to such an AED function, the communication between the radiation image detecting device and the radiation generating device communicates the timing signal for notifying the start timing of the radiation irradiation because the radiation image detecting device and the radiation generating device are different manufacturers. Even when this can not be performed, it is possible to cause the sensor panel to start the pixel charge storage operation according to the radiation start timing of the radiation.

In the AED operation described in Patent Document 1, nine MUXs and ADCs that respectively handle pixels of 256 columns operate in parallel at the same timing to read out the charges of all the columns. This point is similar to the image reading operation.

International Publication No. 2012/008229

The image reading operation is ended if the radiation image for one screen is read once. On the other hand, the AED operation continues from before the start of the radiation irradiation until the start of the irradiation, in order to wait for the start of the irradiation of the radiation whose timing is indefinite. For example, while the image reading operation is completed in the order of several hundreds of msec, the AED operation is an irradiation that instructs the start of radiation irradiation after the operator sets the radiation irradiation conditions in the radiation generating apparatus. It lasts for a few seconds to a few tens of seconds until the switch is pressed.

In Patent Document 1, while the AED operation continues, the signal processing circuit repeats the same operation as the image reading operation for reading out the charges of the pixels of all the columns, so the AED operation has a long operation time with respect to the image reading operation. In the period of, there was a problem that the power consumption was very high. In particular, when the radiation image detection device is a battery-operated electronic cassette, a battery with a limited charge capacity is used, so if the power consumption is high, the battery must be charged frequently, and the imaging efficiency is high. It gets worse.

An object of the present invention is to provide a radiation image detection apparatus capable of reducing the power consumed by a signal processing circuit in an irradiation start detection operation for detecting the start of irradiation of radiation and an operation method thereof.

In order to solve the above problems, in the radiation image detecting apparatus according to the present invention, a plurality of pixels each of which charges in response to radiation emitted from a radiation generating apparatus and transmitted through a subject and stores charges are two-dimensionally arrayed. A sensor panel in which signal lines are disposed, a signal processing circuit that performs signal processing by reading out analog voltage signals corresponding to charges from pixels through the signal lines, and a plurality of charge amplifiers included in the signal processing circuit, A plurality of charge amplifiers provided for each signal line and connected to one end of the signal line and converting charges from pixels into analog voltage signals, and a multiplexer included in a signal processing circuit, the plurality of input terminals A plurality of charge amplifiers are respectively connected to the plurality of input terminals, and sequentially select and output analog voltage signals from the plurality of charge amplifiers. An AD converter included in the signal processing circuit, which is connected to the subsequent stage of the multiplexer and performs AD conversion processing for converting an analog voltage signal output from the multiplexer into a digital signal according to the voltage value A converter and a control unit that controls the signal processing circuit to execute the irradiation start detection operation and the image readout operation, and the irradiation start detection operation is set in advance among the pixels before the start of irradiation of radiation. The charge read out through the detection channel which is a signal line connected to the detection pixel, is an operation to detect the start of radiation irradiation based on the digital signal corresponding to the read charge, and the image readout operation is radiation irradiation After the start, after a pixel charge accumulation period for accumulating charges in the pixels has elapsed, the charges are read out from the pixels through the signal line and read out. And the control unit is connected to the detection channel among the plurality of charge amplifiers connected to the multiplexer in the irradiation start detection operation. The analog voltage signal from some of the charge amplifiers including the detection charge amplifier which is the charge amplifier is selectively output to the AD converter, and the control unit is selectively output to the AD converter. The controller performs only AD conversion processing to an analog voltage signal, and the control unit further reduces the number of pulses per unit time of the clock signal that defines the operation timing of the AD converter than when reading out the image, and further controls In the case where the power supplied to the charge amplifier during the image reading operation is the normal power in the irradiation start detection operation, the Drive at least one of the charge amplifiers in the low power state where power less than normal power and greater than 0 is supplied.

The multiplexer preferably has a function of selecting an analog voltage signal from a part of the plurality of charge amplifiers connected.

A first path for outputting an analog voltage signal from the charge amplifier to the AD converter through the multiplexer, and a second path for outputting the analog voltage signal from the charge amplifier to the AD converter without the multiplexer The control unit preferably controls the switch to select the second path during the irradiation start detection operation, and has a switch that selectively switches the first path and the second path.

In the irradiation start detection operation, the control unit supplies at least one of a plurality of non-selected charge amplifiers other than a part of the charge amplifiers among the plurality of charge amplifiers connected to the multiplexer, and the power supply is lower than the normal power It is preferable to be in a power saving state.

The power saving state is preferably a low power state in which power lower than normal power and greater than 0 is supplied. Alternatively, the power saving state is preferably a power-off state in which the supply of power is stopped.

The control unit preferably puts all of the unselected charge amplifiers in the power saving state.

Control includes a first path for inputting charge to the charge amplifier, a second path for outputting charge to the multiplexer without passing through the charge amplifier, and a switch for selectively switching between the first path and the second path. For the non-selected charge amplifier in the power saving state, the unit preferably controls the switch to select the second path.

When the power saving state is a power off state in which the supply of power is stopped, the control unit stabilizes the potential of the input stage with respect to the non-selected charge amplifier in the power off state. It is preferable to apply a bias voltage.

The control unit includes a plurality of blocks including one multiplexer to which at least one detection charge amplifier is connected and one AD converter connected to the subsequent stage of one multiplexer. Power supply between the first state supplying the first power and the second state supplying the second power whose power per unit time is lower than the first power. Preferably, the power supply state of at least one of the plurality of blocks is periodically switched during the irradiation start detection operation.

When there are two or more blocks in which the power supply state periodically switches, the control unit preferably shifts the timing of switching the power supply state of at least two of the two or more blocks.

The two or more blocks are divided into groups, and the control unit preferably shifts the timing of switching the power supply state for each group. In this case, at least one block is preferably disposed between two blocks belonging to the same group.

The control unit preferably shifts the timing of switching of the power supply state of all the power of two or more blocks.

The control unit preferably keeps at least one of the blocks including the multiplexer to which a part of the charge amplifiers is not connected among the plurality of blocks in the second state during the irradiation start detection operation.

It is preferable that the block is provided for each area configured by pixels connected to a plurality of adjacent signal lines. In this case, it is preferable that a plurality of adjacent blocks, each in charge of an adjacent area, be mounted on the same chip, and a plurality of chips be provided.

The control unit preferably switches the power supply state of the block on a block basis or a chip basis in charge of the area.

The detection pixel is preferably a dedicated pixel specialized for the irradiation start detection operation.

It is preferable to include a temperature drift correction unit that corrects the temperature drift of the digital signal caused by the temperature distribution deviation generated in the signal processing circuit due to switching the power supply state of the block.

It is preferable that the sensor panel and the signal processing circuit be an electronic cassette which is housed in a portable case and is supplied with power from a battery mounted on the case.

According to the operation method of the radiation image detecting apparatus of the present invention, the pixels for accumulating charges in response to radiation emitted from the radiation generating apparatus and transmitted through the object are two-dimensionally arrayed, and a plurality of signal lines for reading out the charges are arranged. A signal processing circuit that performs signal processing by reading an analog voltage signal corresponding to an electric charge from a pixel through a signal line, and a plurality of charge amplifiers included in the signal processing circuit, provided for each signal line A plurality of charge amplifiers connected to one end of the signal line and converting charges from the pixels into analog voltage signals, and a multiplexer included in the signal processing circuit, the plurality of input terminals having a plurality of input terminals; A charge amplifier is connected to each of a plurality of input terminals, and a multiplexer that sequentially selects and outputs analog voltage signals from the plurality of charge amplifiers; An AD converter included in the processing circuit, the AD converter being connected to the subsequent stage of the multiplexer and performing an AD conversion process of converting an analog voltage signal output from the multiplexer into a digital signal according to the voltage value; In an operation method of a radiation image detecting apparatus including a control unit for controlling a signal processing circuit, charge is generated through a detection channel which is a signal line connected to a detection pixel preset among pixels before starting radiation irradiation. And a radiation start detection step of performing radiation start detection operation of detecting radiation start based on a digital signal corresponding to the read charge, and pixel charge accumulation for storing charge in the pixel after radiation radiation start is started. After the period has elapsed, the charge is read from the pixel through the signal line, and a digital signal corresponding to the read charge is displayed. And an image reading step of executing an image reading operation for outputting a radiation image to be diagnosed, and in the irradiation start detecting step, the charge amplifier connected to the detection channel among the plurality of charge amplifiers connected to the multiplexer. Analog voltage signals from some charge amplifiers including a detection charge amplifier are selectively output to the AD converter, and AD conversion to the analog voltage signals selectively output to the AD converter Only the processing is executed, and furthermore, the number of pulses per unit time of the clock signal that defines the operation timing of the AD converter is reduced as compared to that at the image readout, and furthermore, in the irradiation start detection operation, If the power supplied to the charge amplifier is normal power, At least one is driven in a low power state where less than normal power and greater than 0 power is supplied.

According to the present invention, in the irradiation start detection operation for detecting the irradiation start of radiation, the charge amplifier connected to the detection channel of the detection pixel for irradiation start detection among the plurality of charge amplifiers connected to the multiplexer Analog voltage signals from some charge amplifiers including a detection charge amplifier are selectively output to the AD converter, and AD conversion to the analog voltage signals selectively output to the AD converter Only the processing is executed, and furthermore, the number of pulses per unit time of the clock signal that defines the operation timing of the AD converter is reduced as compared to that at the image readout, and furthermore, in the irradiation start detection operation, When the power supplied to the charge amplifier is normal power, at least one of the charge amplifiers is The radiation image detection apparatus capable of reducing the power consumed by the signal processing circuit in the irradiation start detection operation and operating in a low power state in which the power is supplied lower than the above value and larger than 0 is supplied. Can be provided.

It is a figure which shows a radiography system. It is a figure which shows a photography order. It is a figure which shows a menu * condition table. It is an external appearance perspective view of an electronic cassette. It is a block diagram which shows the electric constitution of an electronic cassette. It is a circuit diagram of CA and CDS. It is a block diagram which shows the detail of a gate drive part, a MUX part, and an ADC part. FIG. 6 is a diagram showing a chip on which four adjacent ADCs, each serving an adjacent area, are mounted. FIG. 9A is a diagram showing a digital signal read procedure by the first MUX and the first ADC, FIG. 9A is a first column, FIG. 9B is a second column, FIG. 9C is a third column, and FIG. Show how It is a figure which shows the flow of the operation | movement which a control part performs. It is a figure which shows the gate pulse in pixel reset operation and image read-out operation. It is a figure which shows the supply state of the electric power of ADC in image read-out operation. It is a figure which shows the gate pulse in AED operation | movement. It is a figure which shows the supply state of the electric power of ADC in AED operation. It is a graph which shows the power supply to ADC. It is a graph which shows the number per unit time of ADC of the 1st state of AED operation and image read-out operation. It is a flowchart which shows the operation | movement procedure of an electronic cassette. It is a figure which shows the supply state of the electric power of ADC in AED operation | movement of 1st-2 embodiment. It is a figure which shows the supply state of the electric power of ADC in AED operation | movement of 1st-3 embodiment. It is a figure which shows the supply state of the electric power of ADC in AED operation | movement of 1st-4th embodiment. It is a figure which shows the supply state of the electric power of ADC in AED operation | movement of 1st-5 embodiment. It is a figure which shows the supply state of the electric power of ADC in AED operation | movement of 1st-6 embodiment. FIG. 18 is a diagram showing another example of the power supply state of the ADC in the AED operation of the first to sixth embodiments. It is a figure which shows the supply state of the electric power of ADC in AED operation | movement of 1-7 embodiment. FIG. 18 is a block diagram showing a first to eighth embodiment in which a detection channel which is a signal line to which a detection pixel used for AED operation is connected is set. It is a figure which shows the supply state of the electric power of ADC in AED operation | movement of 1st-8 embodiment. FIG. 18 is a diagram showing another example of the power supply state of the ADC in the AED operation of the first to eighth embodiments. It is a figure which shows the example of arrangement | positioning of the pixel for a detection. It is a block diagram which shows the example of the detection pixel only for AED operation | movement. It is a block diagram which shows another example of the detection pixel only for AED operation | movement. It is a block diagram which shows another example of the detection pixel only for AED operation | movement. It is a figure which shows the example of a setting of the pixel for a detection. It is a flowchart which shows the drive procedure of CDS at the time of image read-out operation. It is a flowchart which shows the drive procedure of CDS at the time of AED operation | movement. It is a circuit diagram showing another example of connection of CDS, MUX, and ADC. It is a graph which shows temperature distribution in the column direction of a signal processing circuit. It is a graph which shows the charge component of the channel for detection. FIG. 14 is a diagram showing a first embodiment of the invention in which the leak charge correction and the temperature drift correction are performed. It is a figure which shows the time of AED operation | movement of 1-13th embodiment which switches transmission I / F of a digital signal. It is a figure which shows the time of the image read-out operation | movement of 1-13th embodiment. It is a schematic block diagram of 2nd-1 embodiment. It is a graph of the power supply to CA. It is a flowchart which shows the operation | movement procedure of the electronic cassette of 2nd-1 embodiment. It is a graph which shows another example of the power supply to CA. It is a figure which shows the structure of the channel for non-detection in the case of making CA for non-detection in the time of AED operation into the state of a power-off. It is a figure which shows the structure of the channel for non-detection in the case of making CA for non-detection in the time of image read-out operation into the state of a power-off. It is a graph which shows the further another example of the power supply to CA. FIG. 44B is a diagram showing a reading procedure of dose signals by the first MUX and the first ADC in the 3-1 embodiment, FIG. 44A is a first column, FIG. 44B is a third column, FIG. 44C is a fifth column, and FIG. It shows how the eye dose signals are read out. It is a graph which shows the number of pulses per unit time of the clock signal of ADC. FIG. 46A is a diagram showing a clock signal during an image read operation, and FIG. 46B is an AED when the number of pulses per unit time of the clock signal of the ADC during AED operation is reduced compared to that during image read operation. The clock signals at the time of operation are respectively shown. FIG. 47B is a diagram showing a second method of reducing the number of pulses per unit time of the clock signal of the ADC at the time of AED operation compared to at the time of image reading operation, FIG. 47A is a clock signal at the time of image reading operation, FIG. The clock signals at the time of operation are respectively shown. It is a flowchart which shows the operation | movement procedure of the electronic cassette of 3rd Embodiment. It is a figure which shows the circuit structure of the channel for detection at the time of AED operation | movement in 3rd-2 embodiment. It is a figure which shows the circuit structure of the channel for detection at the time of the image read-out operation | movement in 3rd-2 embodiment. FIG. 7 is a diagram showing a power supply state of the block in the case where charge readout is started immediately after switching the block from the non-operation state to the operation state. It is a figure which shows the supply state of the electric power of the block in, when switching from the non-operating state of a block to an operation state is performed predetermined time before the timing which starts read-out of electric charge. It is a flowchart which shows the operation | movement procedure of the electronic cassette of 4th Embodiment. It is a figure which shows the detail of the period which is reading electric charge in case all the signal lines of the area which a block takes charge of are channels for a detection. It is a figure which shows the detail of the period which is reading the electric charge in the case of the general thing in case an odd row | line is a channel for a detection, and a MUX has only a function which selects one row one by one sequentially. FIG. 17 is a diagram showing the details of the charge readout period in the case where the odd column is the detection channel and the MUX has the function of selecting only the analog voltage signal from the detection CA of the detection channel. . It is a figure which shows the example which switches the active state of each block to a non-operating state, before starting reading of the electric charge of each block. It is a figure which shows the example which switches the active state of each block to a non-operating state after completion | finish of readout of the electric charge of each block. It is a figure which shows the example which switches from the working state of each block to a non-working state between the periods which are reading the intermittent electric charge of each block. FIG. 14 is a diagram showing a fourth embodiment of activating all blocks in an active state before detection of an image reading operation after detection of X-ray irradiation start in AED operation; It is a graph which shows the power supply to CA. It is a flowchart which shows the operation | movement procedure of the electronic cassette of 5th invention. It is a graph which shows the number of pulses per unit time of the clock signal of ADC. It is a flowchart which shows the operation | movement procedure of the electronic cassette of 6th invention. It is a block of the 7th invention, and a circuit configuration of the circumference of it, and is a figure showing the state at the time of image read-out operation. It is a block of the 7th invention, and a circuit configuration of the circumference of it, and is a figure showing the state at the time of AED operation.

1. 1st invention [1-1st embodiment]
In FIG. 1, an X-ray imaging system 10 for performing imaging using X-rays as radiation includes an X-ray generator 11 and an X-ray imaging apparatus 12 and is installed, for example, in an imaging room of a radiology department in a medical facility. Ru. The X-ray generator 11 includes an X-ray source 13, a radiation source controller 14 that controls the X-ray source 13, and an irradiation switch 15 connected to the radiation source controller 14. The X-ray imaging apparatus 12 has an electronic cassette 16 which is a radiation image detection apparatus, and a console 17.

In the imaging room, in addition to the X-ray imaging system 10, a standing imaging stand 18 for imaging the patient P who is the subject in a standing posture and a lying imaging stage 19 for imaging the patient P in a lying posture It is done. The X-ray source 13 is shared by the standing position imaging stand 18 and the reclining position imaging stand 19. Note that FIG. 1 shows that the electronic cassette 16 is set on the standing imaging stand 18 and X-ray imaging of the patient P is performed in the standing posture.

As well known, the X-ray source 13 includes an X-ray tube that generates X-rays, and a radiation field limiter (also called a collimator) that limits the radiation field of X-rays generated from the X-ray tube to the patient P. Have. The source controller 14 controls the tube voltage, the tube current, and the irradiation time of the X-ray applied to the X-ray tube. A plurality of types of X-ray irradiation conditions consisting of a tube voltage, a tube current, and an irradiation time are stored in advance in the radiation source control device 14 in accordance with the imaging site such as the chest and abdomen. The conditions are selectively input by the operator. The irradiation conditions can be finely adjusted by the operator in consideration of the type of the patient P and the like.

The irradiation switch 15 is operated by the operator when starting the irradiation of X-rays. The irradiation switch 15 is a two-stage depression type, and when the irradiation switch 15 is depressed (half-pressed) to the first stage, the radiation source control device 14 performs a preparation operation before irradiating the X-ray source 13 with X-rays. To start. When the irradiation switch 15 is pushed to the second stage (full pushing), the radiation source control device 14 starts the irradiation of X-rays by the X-ray source 13. The radiation source control device 14 has a timer that starts timing when X-ray irradiation is started, and when the time counted by the timer reaches the irradiation time set in the irradiation condition, X by the X-ray source 13 Stop irradiation of the line.

The electronic cassette 16 detects an X-ray image based on the X-ray irradiated from the X-ray source 13 and transmitted through the patient P. The console 17 is configured by installing a control program such as an operating system and various application programs based on a computer such as a notebook personal computer, for example. The console 17 has a display 20 and an input device 21 such as a touch pad or a keyboard. The console 17 displays various operation screens provided with operation functions by GUI (Graphical User Interface) on the display 20, and accepts input of various operation instructions by the operator from the input device 21 through the various operation screens.

The electronic cassette 16 and the console 17 include

wireless communication units

22 and 23 for wireless communication with each other. The electronic cassette 16 and the console 17 wirelessly communicate various information including an imaging menu and an X-ray image through the

wireless communication units

22 and 23.

Each of the

wireless communication units

22 and 23 includes an antenna, a modulation / demodulation circuit, a transmission control unit, and the like. The modulation and demodulation circuit performs modulation for loading data to be transmitted on a carrier (also referred to as a carrier) and demodulation for extracting data from the carrier received by the antenna. The transmission control unit performs transmission control in accordance with the wireless local area network (LAN) standard.

The console 17 receives an input of an imaging order for instructing the operator to perform X-ray imaging. The imaging order is input to the console 17 from, for example, a Radio Information System (RIS) (not shown).

In FIG. 2, the imaging order has items such as order ID (Identification Data), patient ID, imaging region / posture / direction, and the like. The order ID is a symbol or a number that identifies each imaging order, and is automatically assigned by the RIS. The patient ID of the patient P to be imaged is described in the item of patient ID. The patient ID is a symbol or a number identifying the individual patient P.

The imaging region / posture / direction item describes the imaging region, posture, and imaging direction specified by the doctor who issued the imaging order. The site to be imaged is a part of the human body such as the head, cervical spine, chest, abdomen, hands, fingers, elbows, knees and the like. The posture is the posture of the patient P such as standing position, lying position, sitting position, etc., and the imaging direction is the direction of the patient P with respect to X-rays such as front, side, back and the like. Although illustration is omitted, in the imaging order, in addition to the above-described items, items of patient information such as the name, sex, age, height, and weight of the patient P are provided. The medical department that issued the imaging order, the doctor who issued the imaging order, the date and time when the imaging order was received by RIS, the purpose of imaging such as postoperative follow-up observation and evaluation of the effect of the therapeutic agent, and matters passed to the operator from the doctor An item may be provided.

Note that there may be one imaging order for one patient P or multiple imaging orders for one patient P at the same time. When a plurality of imaging orders are issued simultaneously to one patient P, an identification code indicating that the imaging order is for one patient P is attached to the order IDs of the plurality of imaging orders.

The console 17 stores a menu / condition table 25 shown in FIG. In the menu / condition table 25, an imaging menu in which an imaging region, an attitude, and an imaging direction form one set is associated with an irradiation condition corresponding thereto and registered. Note that an imaging menu in which the imaging region excluding the posture from the above imaging menu and the imaging direction become one set or an imaging menu corresponding to special imaging such as tomosynthesis imaging may be provided.

The console 17 displays the photographing order list in which the contents of the photographing order shown in FIG. 2 are listed on the display according to the operation of the operator. The operator browses the imaging order list and confirms the contents of the imaging order. Next, the console 17 displays the contents of the menu / condition table 25 on the display in a form in which the shooting menu can be set. The operator selects and sets the imaging menu that matches the imaging region / posture / direction specified in the imaging order. In addition, the operator sets, in the radiation source control device 14, the irradiation condition corresponding to the irradiation condition corresponding to the selected imaging menu.

The console 17 wirelessly communicates various information such as a shooting menu set by the operator, an irradiation condition corresponding to the set shooting menu, an order ID, a console ID which is a symbol or a number identifying itself, and a shooting preparation instruction. The electronic cassette 16 is transmitted via the unit 23.

In addition, the console 17 converts the X-ray image from the electronic cassette 16 into an image file of a format conforming to, for example, DICOM (Digital Imaging and Communication in Medicine) standard, and this is a medical image storage communication system (PACS; Picture Archiving and Communication) Send to System (not shown). In the image file, an X-ray image is associated with image incidental information such as order ID, patient information, imaging menu, irradiation condition, cassette ID which is a symbol or number identifying the electronic cassette 16 by one image ID. It is a thing. The doctor of the medical department who has issued the imaging order can access the PACS with a terminal of the medical department or the like to download the image file and view the X-ray image.

In FIG. 4, the electronic cassette 16 is configured of a sensor panel 30, a circuit unit 31, and a portable housing 32 having a rectangular parallelepiped shape for housing these components. The housing 32 has a size in conformity with the International Standard for International Organization for Standardization (ISO) 4090: 2001, which is substantially the same as, for example, a film cassette, an imaging plate (IP) cassette, and a computed radiography (CR) cassette. In the housing 32, in addition to the sensor panel 30 and the circuit section 31, the wireless communication section 22 described above, the battery 65 (see FIG. 5) for supplying power to each section of the electronic cassette 16, and the console 17 and cable A wired communication unit 66 (see FIG. 5) and the like for wired connection via the communication channel are accommodated. When the wireless communication unit 22 is used, the electronic cassette 16 is driven by the power from the battery 65 and can be used wirelessly.

A rectangular opening is formed in the front surface 32A of the housing 32, and a transmission plate 33 having X-ray transparency is attached to the opening. The electronic cassette 16 is positioned with the X-ray source 13 and the front surface 32A facing each other. Although not shown, the housing 32 is provided with a switch for switching the power on / off, and an indicator for notifying the operating state of the electronic cassette 16 such as the remaining use time of the battery 65 and the shooting preparation completion state. .

The sensor panel 30 is composed of a scintillator 34 and a light detection substrate 35. The scintillator 34 and the light detection substrate 35 are stacked in the order of the scintillator 34 and the light detection substrate 35 as viewed from the front surface 32A where X-rays are incident. The scintillator 34 has phosphors such as CsI: Tl (thallium activated cesium iodide) and GOS (Gd ₂ O ₂ S: Tb, terbium activated gadolinium oxysulfide), etc., and receives X rays incident through the transmission plate 33. Convert to visible light and emit. A sensor panel may be used in which the light detection substrate 35 and the scintillator 34 are stacked in order as viewed from the front surface 32A where X-rays are incident. Alternatively, a direct conversion type sensor panel may be used in which X-rays are directly converted into electric charges by a photoconductive film such as amorphous selenium.

The light detection substrate 35 detects visible light emitted from the scintillator 34 and converts it into a charge. The circuit unit 31 controls driving of the light detection substrate 35 and generates an X-ray image based on the charge output from the light detection substrate 35.

In FIG. 5, the light detection substrate 35 includes pixels 40 arranged in a two-dimensional matrix of N rows and M columns, N gate lines 41, and M signals on a glass substrate (not shown). And a line 42 is provided. The gate lines 41 extend in the X direction along the row direction of the pixels 40 and are arranged at a predetermined pitch in the Y direction along the column direction of the pixels 40. The signal lines 42 extend in the Y direction and are arranged at a predetermined pitch in the X direction. The gate line 41 and the signal line 42 are orthogonal to each other, and the pixel 40 is provided corresponding to the intersection of the gate line 41 and the signal line 42.

N and M are integers of 2 or more. In this example, N = 2880 and M = 2304 (see FIG. 7) will be described. Note that the number of matrices of the pixels 40 is not limited to this. Further, the arrangement of the pixels 40 does not have to be the square arrangement as shown in FIG. 5, and the pixels 40 may be inclined 45 ° and the pixels 40 may be arranged in a staggered manner.

Each pixel 40 includes a photoelectric conversion unit 43 generating charges (electron-hole pairs) upon incidence of visible light and storing the charge, and a TFT (Thin Film Transistor) 44 as a switching element, as is well known. . The photoelectric conversion unit 43 has a structure in which an upper electrode and a lower electrode are disposed above and below the semiconductor layer generating charges. The semiconductor layer is, for example, a PIN (p-intrinsic-n) type, and an N-type layer is formed on the upper electrode side and a P-type layer is formed on the lower electrode side. The TFT 44 has a gate electrode connected to the gate line 41, a source electrode connected to the signal line 42, and a drain electrode connected to the lower electrode of the photoelectric conversion unit 43. Note that as a type of switching element, a complementary metal oxide semiconductor (CMOS) type sensor panel may be used instead of the TFT type.

A bias line (not shown) is connected to the upper electrode of the photoelectric conversion unit 43. A positive bias voltage is applied to the upper electrode through the bias line. The application of a positive bias voltage generates an electric field in the semiconductor layer. Therefore, the electrons of the electron-hole pairs generated in the semiconductor layer by photoelectric conversion move to the upper electrode and are absorbed by the bias line, and the holes move to the lower electrode and are collected as charge. .

The circuit unit 31 is provided with a gate drive unit 50, a signal processing circuit 51, a memory 52, a power supply unit 53, and a control unit 54 for controlling these.

The gate driver 50 is connected to an end of each gate line 41 and emits gate pulses G (R) (R = 1 to N) for driving the TFTs 44. The control unit 54 drives the TFT 44 through the gate drive unit 50 and controls the signal processing circuit 51 to read out the dark charge from the pixel 40 and reset (discard) the dark charge, and the received dose of the X-ray. A pixel charge accumulation operation for accumulating corresponding charges in the pixels 40, an image reading operation for reading an X-ray image to be used for diagnosis, and an AED operation for detecting the start of X-ray irradiation are executed.

The image readout operation reads out the charge from the pixel 40 through the signal line 42 after the pixel charge accumulation period has elapsed after the start of X-ray irradiation, and outputs an X-ray image represented by the digital signal corresponding to the read out charge. It is an operation. On the other hand, the AED operation is an operation of reading out the charge from the pixel 40 through the signal line 42 before the start of the X-ray irradiation and detecting the start of the X-ray irradiation based on the digital signal corresponding to the read charge.

The signal processing circuit 51 reads an analog voltage signal V (C) (C = 1 to M) corresponding to the charge from the pixel 40 through the signal line 42 and performs signal processing. The signal processing circuit 51 includes a CA 60, a correlated double sampling circuit (hereinafter referred to as CDS (Correlated Double Sampling)) 61, a MUX unit 62, and an ADC unit 63.

The CA 60 is provided for each signal line 42 and is connected to one end of the signal line 42. The CA 60 outputs an analog voltage signal V (C) according to the charge flowing from the pixel 40 through the signal line 42. The CDS 61 is provided for each signal line 42 in the same manner as the CA 60. The CDS 61 performs well-known correlated double sampling processing on the analog voltage signal V (C) from the CA 60 to remove the reset noise component of the CA 60 from the analog voltage signal V (C).

The CA 60 is connected to the MUX unit 62. The CDS 61 is disposed between the CA 60 and the MUX unit 62. Further, an ADC unit 63 is connected to the subsequent stage of the MUX unit 62. The MUX unit 62 sequentially selects analog voltage signals V (C) from the plurality of CAs 60 input via the CDS 61, and outputs the selected analog voltage signal V (C) to the ADC unit 63. The ADC unit 63 executes AD conversion processing for converting the analog voltage signal V (C) from the MUX unit 62 into a digital signal DS (C) according to the voltage value. Then, the converted digital signal DS (C) is output to the memory 52. The memory 52 stores the digital signal DS (C) from the ADC unit 63. The memory 52 has a capacity for storing at least one screen of X-ray images.

The power supply unit 53 supplies the power from the battery 65 to each unit under the control of the control unit 54. For example, the battery 65 is detachably mounted on the back surface of the housing 32 opposite to the front surface 32A.

The control unit 54 receives various information from the console 17 received by the wireless communication unit 22 or the wired communication unit 66, and performs control according to the various information. For example, the control unit 54 changes the processing condition of the signal processing circuit 51 according to the irradiation condition.

In FIG. 6, the CA 60 includes an operational amplifier 70, a capacitor 71, and an amplifier reset switch 72. The operational amplifier 70 has two input terminals and one output terminal. The signal line 42 is connected to one of the two input terminals, and the ground line is connected to the other. The capacitor 71 and the amplifier reset switch 72 are connected in parallel between the input terminal to which the signal line 42 is connected and the output terminal.

The CA 60 integrates the charges flowing from the signal line 42 by accumulating it in the capacitor 71, and outputs a voltage value corresponding to the integrated value, that is, an analog voltage signal V (C). The unpreset switch 72 is drive-controlled by the control unit 54. By turning on the unpreset switch 72, the charge accumulated in the capacitor 71 is reset (discarded).

The CDS 61 includes a first sample and hold circuit (hereinafter abbreviated as S / H) 73A and a second S / H 73B, and a differential amplifier 74. The first S / H 73A samples and holds the reset noise component of the CA 60 when the TFT 44 is off. The second S / H 73B samples and holds the analog voltage signal V (C) output from the CA 60 based on the charge that flows in when the TFT 44 is turned on. The differential amplifier 74 takes the difference between the reset noise component held by both S /

Hs

73A and 73B and the analog voltage signal V (C). As a result, an analog voltage signal V (C) from which noise has been removed is output.

In FIG. 7, the gate drive unit 50 has, for example, a total of twelve gate drive circuits 75, the first to twelfth. Each gate drive circuit 75 shares each gate line 41. Since the row N of the pixels 40 is equal to 2880, the first gate drive circuit 75 includes the gate lines 41 of the first to 240th rows of the pixels 40, and the second gate drive circuit 75 includes the 241st to 480th rows. As in the

gate line

41, 2880/12 = 240 gate lines 41 are connected to one gate drive circuit 75. Therefore, one gate drive circuit 75 takes charge of reading out the charge from the pixels 40 for 240 rows.

The MUX unit 62 has, for example, first to sixteenth sixteen MUXs 76 in total. Each MUX 76 shares each signal line 42. Since the column M of the pixel 40 is equal to 2304, the signal line 42 in the first to 144th columns of the pixel 40 is for the first MUX 76, the signal line 42 for the 145th to 288th columns for the second MUX 76, and so on. 2304/16 = 144 signal lines 42 are connected to one MUX 76. Therefore, one MUX 76 selectively outputs an analog voltage signal V (C) based on the charges from the pixels 40 for 144 columns. Hereinafter, an area constituted by the pixels 40 connected to the plurality of adjacent signal lines 42 is referred to as an area AR (AR1 to AR16).

Each MUX 76 has a plurality of input terminals. A plurality of CAs 60 are connected to the plurality of input terminals with the CDS 61 interposed therebetween.

Similar to the first to sixteenth MUXs 76 of the MUX unit 62, the ADC unit 63 includes first to sixteenth ADCs 16 in total. The first to sixteenth ADCs 77 are connected to the subsequent stages of the first to sixteenth MUXs 76, respectively. Since the first to sixteenth MUXs 76 are provided for each of the areas AR1 to AR16, the first to sixteenth ADCs 77 are also provided for each of the areas AR1 to AR16.

The first ADC 77 converts analog voltage signals V (1) to V (144) sequentially output from the first MUX 76 into digital signals DS (1) to DS (144), and the second ADC 77 outputs analog sequentially output from the second MUX 76 , And converts one of the voltage signals V (145) to V (288) into the digital signals DS (145) to DS (288). It shares the AD conversion process of the signal DS (V).

As shown in FIG. 8, one MUX 76, a plurality of CAs 60 and CDSs 61 connected to its input terminal, and one ADC 77 connected to the output terminal of the MUX 76 constitute one block BL. There are 16 blocks BL as many as the area AR.

As shown by a broken line, blocks BL1 to BL4 configured of CA 60, CDS 61, MUX (first to fourth MUX) 76, and ADC (first to fourth ADC) 77 that respectively handle four adjacent areas AR1 to AR4. Are mounted on the same chip CP1. Similarly, blocks BL5 to BL8 configured of CA60, CDS 61, MUX (fifth to eighth MUX) 76 and ADC (fifth to eighth ADC) 77 in charge of areas AR5 to AR8 are mounted on chip CP2. ing. Blocks BL9 to BL12 configured with CA 60, CDS 61, MUX (ninth to 12th MUX) 76 and ADC (9th to 12th ADC) 77 respectively responsible for the areas AR9 to AR12 are mounted on the chip CP3. Blocks BL13 to BL16 configured with CA 60, CDS 61, MUXs (13 to 16 MUXs) 76, and ADCs (13 to 16 ADCs) 77 respectively responsible for the areas AR13 to AR16 are mounted on the chip CP4. These chips CP1 to CP4 are physically completely separated.

Note that the number of gate drive circuits 75 and the number of rows of pixels 40 which one gate drive circuit 75 is in charge of are not limited to 12 and 240 in this example. Similarly, the number of MUXs 76 and ADCs 77 (number of blocks BL), and the number of columns of pixels 40 that one MUX 76 and ADC 77 takes charge of (the number of columns of pixels 40 included in one block BL) The number of blocks BL constituting one chip CP is not limited to this example, and is arbitrary. For example, the number of columns of the pixels 40 included in one block BL may be 256, and the number of blocks BL may be nine. Further, the number of columns of the pixels 40 included in one block BL may be 128 columns, and the number of blocks BL may be eighteen.

FIG. 9 shows a reading procedure of the digital signals DS (1) to DS (144) of the area AR1 of the first to 144th columns as an example. In FIG. 9, analog voltage signals V (1) to V (144) after reset noise removal corresponding to the charges read from the pixel 40 through the signal line 42 appear at the output terminal of the CDS 61. It shows.

In this state, first, as shown in FIG. 9A, the first MUX 76 selects the analog voltage signal V (1) in the first column. Accordingly, the analog voltage signal V (1) is input to the first ADC 77, and is converted into the digital signal DS (1) by the first ADC 77. Next, as shown in FIG. 9B, the first MUX 76 selects the analog voltage signal V (2) in the second column. Accordingly, the analog voltage signal V (2) is input to the first ADC 77, and is converted into the digital signal DS (2) by the first ADC 77. Subsequently, as shown in FIG. 9C, the first MUX 76 selects the analog voltage signal V (3) in the third column. As a result, the analog voltage signal V (3) is input to the first ADC 77, and is converted into the digital signal DS (3) by the first ADC 77.

By repeating this series of operations in the first MUX 76 and the first ADC 77, the voltage signal V (144) in the 144th column is finally converted to the digital signal DS (144) as shown in FIG. 9D. The reading of the digital signals DS (1) to DS (144) in the area AR1 in the first to 144th columns is completed. The same applies to each MUX 76 and each ADC 77 of the other areas AR2 to AR16.

As shown in FIG. 10, when the control unit 54 receives from the wireless communication unit 22 or the wired communication unit 66 a shooting preparation instruction that is various information including a shooting menu from the console 17, the control unit 54 starts the AED operation. In the AED operation, the signal processing circuit 51 converts the charge generated in the photoelectric conversion unit 43 of the pixel 40 into a digital signal DS (C) and stores the digital signal DS (C) in the memory 52. The digital signal DS (C) stored in the memory 52 in the AED operation is hereinafter referred to as a dose signal DDS (C). The control unit 54 performs a standby operation before receiving a shooting preparation instruction. In the standby operation, only the bias voltage is applied to the upper electrode of the photoelectric conversion unit 43, and power is not supplied to the signal processing circuit 51 and the like.

The dose signal DDS (C) is repeatedly read at predetermined intervals. The dose signal DDS (C) obtained by one reading corresponds to the incident dose of X-rays per unit time. When the X-ray irradiation is started, the X-ray incident dose per unit time gradually increases, and accordingly, the value of the dose signal DDS (C) also increases.

Every time the dose signal DDS (C) is stored in the memory 52, the control unit 54 reads the dose signal DDS (C) from the memory 52, and the dose signal DDS (C) and an irradiation start determination threshold value preset. Compare the size of When the dose signal DDS (C) becomes larger than the irradiation start determination threshold value, the control unit 54 determines that the X-ray irradiation has been started. As a result, the electronic cassette 16 can detect the start of X-ray irradiation without receiving a timing signal for reporting the X-ray irradiation start timing from the radiation source controller 14.

When the start of X-ray irradiation is detected, the control unit 54 performs a pixel charge accumulation operation after performing a pixel reset operation (not shown in FIG. 10). The control unit 54 has a timer that starts counting when it detects the start of X-ray irradiation, similarly to the radiation source control device 14, and the time measured by the timer is the irradiation time of the irradiation condition set by the console 17. When it becomes, it determines with irradiation of X-ray having been completed. When the control unit 54 detects the end of the X-ray irradiation, the control unit 54 ends the pixel charge accumulation operation and performs the image read operation. Thus, one X-ray imaging for obtaining one screen of X-ray images is completed. After the end of the image reading operation, the control unit 54 returns to the standby operation again.

As shown in FIG. 11, in the pixel reset operation and the image readout operation, gate pulses G (R) are applied to the gate lines 41 from the gate drive circuit 75 in order from the first row to the 2880th row. In the pixel reset operation, the charge from the pixel 40 flows through the signal line 42 to the capacitor 71 of the CA 60 and is accumulated, but this charge is discarded without being read out by the operation of the amplifier reset switch 72.

On the other hand, in the image reading operation, as shown in FIG. 9, the digital signal DS (C) based on the charge from the pixel 40 is read and stored in the memory 52 as an X-ray image to be used for diagnosis. Hereinafter, in order to distinguish the digital signal DS (C) read out in the image reading operation from the dose signal DDS (C) in the AED operation, it is expressed as the image signal DIS (C).

As shown in FIG. 12, the control unit 54 places all of the first to sixteenth ADCs 77 in the operating state (corresponding to the first state) during the image reading operation. Then, during the image reading operation, the first to sixteenth ADCs 77 are operated in parallel at the same timing. The first to sixteenth MUXs 76 connected to the first to sixteenth ADCs 77 are also activated during the image reading operation and operated in parallel at the same timing. Therefore, in the image reading operation, the image signals DIS (C) of the same row are read out at the same timing in order from the top row to the last row of the areas AR1 to AR16. For example, the first column, the 145th column, the 289th column,..., The image signal DIS (1), the DIS (145), the DIS (289),. , DIS (2161) are read at the same timing. Furthermore, the CAs 60 and the CDS 61 connected to the first to sixteenth MUXs 76 are all activated during the image reading operation.

In the standby operation after the end of the image reading operation, the control unit 54 puts all of the first to sixteenth ADCs 77 in the non-operating state (corresponding to the second state). The first to sixteenth MUXs 76, CA 60, and CDS 61 are all deactivated during standby operation.

As shown in FIG. 13, in the AED operation, gate pulses G (R) are simultaneously applied to the respective gate lines 41 of the same row sequentially from the top row to the last row which each of the first to twelfth gate drive circuits 75 takes charge of. Be For example, the first row of the first row of the first gate drive circuit 75, the 241st row of the first row of the second gate drive circuit 75, the 481th row of the first row of the third gate drive circuit 75,. Gate pulses G (1), G (241), G (481),..., G (2639) are simultaneously applied to the gate lines 41 of the 2639th line of the first line of the drive circuit 75, and then the first line On the second line, the 242nd line, the 482nd line,..., The 2640th line of the next line of the gate line 41, gate pulses G (2), G (242), G (482),. G (2640) is given.

Thus, in the AED operation, gate pulses G (R) are simultaneously applied to the gate lines 41 of a total of 12 rows spaced by 240 rows. Therefore, the TFTs 44 in the 12 rows are simultaneously turned on, and the charges from the pixels 40 in the 12 rows are added by the signal lines 42 in each column and input to the CA 60. For this reason, when the generated charges in the respective pixels 40 are the same, the dose signal DDS (C) obtained in the AED operation is approximately 12 times the image signal DIS (C) obtained in the image reading operation. Thereby, the S / N (Signal-to-Noise) ratio of the dose signal DDS (C) can be improved.

The control unit 54 compares the dose signal DDS (C) with the irradiation start determination threshold every time the dose signal DDS (C) based on the charge for 12 rows is stored in the memory 52, and the X-ray irradiation is performed. Determine if it has started. Although the dose signal DDS (C) is output for 2304 columns, the control unit 54 compares the representative value of one of the 2304 dose signals with the irradiation start determination threshold. The representative value is, for example, an average value, a maximum value, a mode value or the like of 2304 dose signals.

In the pixel charge storage operation, the gate pulse G (R) is not applied from the gate drive circuit 75 to the gate line 41, and all the TFTs 44 of each pixel 40 are turned off.

In the pixel reset operation, gate pulses G (R) are not sequentially applied to the gate lines 41 as shown in FIG. 11, but the first to twelfth gate drive circuits 75 are shown in FIG. The gate pulse G (R) may be simultaneously applied to the respective gate lines 41 of the same row in order from the first row to the last row which each is in charge of. Alternatively, the gate pulse G (R) may be simultaneously applied to the gate lines 41 to read out the charge from all the pixels 40 at once.

As shown in FIG. 14, the control unit 54 periodically switches the power supply states of the first to sixteenth ADCs 77, specifically, the operating state and the non-operating state, during the AED operation. In addition, the control unit 54 shifts the timing of switching of the power supply state of the first to sixteenth ADCs 77. Specifically, first, the control unit 54 activates the first, fifth, ninth, and thirteenth ADCs 77 at the top of each of the chips CP1 to CP4, and switches to the inoperative state after the time T has elapsed. At the same time as this switching, the second, sixth, tenth and fourteenth ADCs 77 adjacent to each other are activated, and similarly switched to the inoperative state after time T has elapsed. Subsequently, after the third, seventh, eleventh and fifteenth ADCs 77 are in the operating state for time T, the fourth, eighth, twelfth and sixteenth ADCs 77 at the end of each of the chips CP1 to CP4 are in the operating state T for time. Then, switching of the series of power supply states is repeated.

Since the first to sixteenth ADCs 77 are provided for each of the areas AR1 to AR16, FIG. 14 can be said to switch the power supply state of the ADC 77 in units of the ADCs 77 in charge of the area AR. Also, first, fifth, ninth and thirteenth ADCs 77, second, sixth, tenth and fourteenth ADCs 77, third, seventh, eleventh and fifteenth ADCs 77, fourth, eighth, twelfth and twelfth The sixteenth ADCs 77 correspond to groups to which the power supply state is switched at the same timing. In these groups, the timing of the power supply state is shifted. Furthermore, three ADCs 77 are disposed between two ADCs 77 belonging to the same group. For example, a total of three ADCs 77 of the second to fourth ADCs 77 are disposed between the first ADC 77 and the fifth ADC 77 belonging to the same group.

The time T is the time required to read out the dose signal DDS (C) from all 144 columns which are the columns of the pixels 40 that each ADC 77 takes charge in the AED operation. The time required to read out the dose signal DDS (C) from all the 2304 columns (hereinafter referred to as the readout period of the dose signal DDS (C)) is divided into four times for each of the chips CP1 to CP4 to obtain the dose signal DDS (C). Since reading is performed, T × 4 = 4T.

The dose signal DDS (C) obtained by the AED operation is not used as image information of the patient P, unlike the image signal DIS (C) obtained by the image reading operation. Therefore, in the AED operation, as shown in FIG. 13, the gate pulse G (R) is simultaneously applied to the gate lines 41 in a total of 12 rows, and the charges from the pixels 40 in 12 rows are transmitted to the signal lines 42 of each column. It is added by. Further, as shown in FIG. 14, in the AED operation, the power supply state is periodically switched without the first to sixteenth ADCs 77 being always in the operating state as in the image reading operation.

Here, the operating state is a state in which the power PON_A necessary to exhibit the function of the ADC 77 is supplied to the ADC 77, as shown on the right side of FIG. The power PON_A corresponds to the first power. That is, the operating state corresponds to the first state as described above. On the other hand, in the non-operating state, as shown on the left side of FIG. 15, the power PSL_A which is lower than the power PON_A and in which the ADC 77 can not function is supplied to the ADC 77. The power PSL_A corresponds to the second power. That is, the non-operating state corresponds to the second state as described above.

As shown in FIG. 12 and FIG. 14, the control unit 54 has a function of switching the power supply state to the ADC 77 between the operating state which is the first state and the non-operating state which is the second state. There is.

Specifically, the power PON_A required to exert the function of the ADC 77 is the power required at the time of the image reading operation. It should be noted that a state in which power that is lower than the power required at the time of image reading operation but which can exhibit the function of the ADC 77 may be set as the operating state.

Although the power PSL_A has a value of 0 or more in FIG. 15, the power PSL_A may be 0. That is, the power off state where no power is supplied to the ADC 77 may be set as the non-operating state. In addition, the supply of the clock signal that defines the operation timing of the ADC 77 may be stopped, and the state in which the power consumption of the ADC 77 is substantially zero may be set as the non-operation state.

As shown in FIG. 12, in the image reading operation, all of the first to sixteenth ADCs 77 are always in the operating state, so when the unit time is T, the operating state (first state) per unit time T is The number of ADCs 77 is sixteen. On the other hand, as shown in FIG. 14, in the AED operation, four ADCs 77 out of the first to sixteenth ADCs 77 operate at the same timing, so the number of operating ADCs 77 per unit time T is four. . Therefore, as shown in FIG. 16, assuming that the number 16 per unit time T at the time of image reading operation is normalized to 1, the number per unit time T in the AED operation is 4/16 = 0.25, It is reduced compared to the image read operation time.

Although illustration and detailed description will be omitted, the control unit 54 switches the power supply state in conjunction with the ADC 77 also for the ADC 60 and the CA 60, the CDS 61, and the MUX 76 that constitute the block BL.

Next, the operation of the above configuration will be described with reference to the flowchart of FIG. When the operator takes an X-ray image with the X-ray imaging system 10, the power of the electronic cassette 16 is turned on. Control unit 54 executes a standby operation (step ST100).

The operator sets a desired imaging menu via the input device 21 of the console 17. As a result, various information such as the set photographing menu and the irradiation conditions corresponding to the set photographing menu is transmitted from the console 17 to the electronic cassette 16 as a photographing preparation instruction.

After the setting of the imaging menu, the operator finely adjusts the irradiation conditions which are the same as the irradiation conditions corresponding to the set imaging menu or the irradiation conditions corresponding to the set imaging menu according to the physical constitution etc. of the patient P. The source control device 14 is set. The operator sets the electronic cassette 16 on either the standing imaging stand 18 or the reclining imaging stand 19 to position the X-ray source 13, the electronic cassette 16 and the patient P at desired positions. Thereafter, the operator depresses the irradiation switch 15 to drive the X-ray source 13 to irradiate the patient P with X-rays. The order of the setting of the imaging menu and the setting of the irradiation condition and the positioning of the patient P may be reversed.

The radiographing preparation instruction, which is various information including the radiographing menu, is received by the wireless communication unit 22 or the wired communication unit 66, and is received by the control unit 54 (YES in step ST110). After receiving the imaging preparation instruction, the control unit 54 executes the AED operation. During this AED operation, as shown in FIG. 14, the power supply states of the first to sixteenth ADCs 77 are periodically switched (step ST 120, irradiation start detection step).

The control unit 54 compares the magnitude of the dose signal DDS (C) obtained in the AED operation with the irradiation start determination threshold (step ST130). The value of the dose signal DDS (C) increases with the irradiation of the X-rays. When the dose signal DDS (C) becomes larger than the irradiation start determination threshold (YES in step ST130), the control unit 54 determines that the X-ray irradiation has been started (step ST140). Control unit 54 executes a pixel charge storage operation (step ST150). If the dose signal DDS (C) does not become larger than the irradiation start determination threshold within a predetermined time (YES in step ST160) and the power is not turned off (NO in step ST190), the control unit 54 The process returns to the standby operation again (step ST100).

When the control unit 54 detects the start of X-ray irradiation, the timer starts counting time. The pixel charge accumulation operation is continued until the time counted by this timer becomes the irradiation time of the irradiation condition set by the console 17. If the timed time of the timer has become the irradiation time of the irradiation condition (YES in step ST170), control unit 54 executes an image reading operation. During this image reading operation, as shown in FIG. 12, all of the first to sixteenth ADCs 77 are constantly operated (step ST180, image reading step). These series of operations are continued until the power is turned off (YES in step ST190).

The image signal DIS (C) obtained by the image reading operation is transmitted from the wireless communication unit 22 or the wired communication unit 66 to the console 17 as an X-ray image. The x-ray image is displayed on the display 20 for viewing by the operator.

By switching the power supply states of the first to sixteenth ADCs 77, the number of operating ADCs 77 per unit time T in the AED operation is reduced compared to that in the image reading operation, and the signal processing circuit 51 consumes in the AED operation. Power can be reduced.

Conventionally, even in the AED operation, the first to sixteenth ADCs 77 are always in operation as in the image reading operation, and the number of operating ADCs 77 per unit time is the same as in the image reading operation. For this reason, a large amount of power is consumed in the AED operation whose operation time is long as compared with the image reading operation which is ended by reading an X-ray image for one screen once. In particular, in the case of the electronic cassette 16 driven by the battery 65, if the power consumption is large, the battery 65 must be frequently charged, and the imaging efficiency is degraded.

However, in the first invention, it is possible to reduce the power consumed by the signal processing circuit 51 in the AED operation. As a result, the battery 65 lasts longer than before, and the number of times the battery 65 is charged is also reduced, so that the imaging efficiency can be improved.

As a method of reducing the number of operating ADCs 77 per unit time T in the AED operation as compared with the image reading operation, it is conceivable to keep the specific ADC 77 in a non-operating state at all times. However, when a specific ADC 77 is always in a non-operating state, the dose signal DDS (C) of the area AR that the ADC 77 is in charge of is not read out. That is, there is an area AR which can not be covered by the AED operation.

On the other hand, in the present embodiment, as shown in FIG. 14, the power supply states of all the first to sixteenth ADCs 77 are periodically switched, and the number of operating ADCs 77 per unit time T in AED operation is It is reduced compared to the read operation time. Therefore, in addition to the effect that it is possible to reduce the power consumed by signal processing circuit 51 in the AED operation, dose signal DDS (C) can be read out uniformly from all areas AR1 to AR16. The effect that the areas AR1 to AR16 can be covered is obtained.

Also, as another method of reducing the number of operating ADCs 77 per unit time T in the AED operation as compared with the image reading operation, a specific ADC 77 is always operated and the remaining ADCs 77 are always not operated. It is also conceivable to do. However, the power consumption of the signal processing circuit 51 can be further reduced by periodically switching the power supply state as in the first to sixteenth ADCs 77 of this embodiment without constantly putting the specific ADC 77 into the operating state. It is clear that it is possible.

From the above, in the AED operation, periodically switching the power supply state of at least one of the plurality of ADCs 77 means that the specific ADC 77 is always in a non-operating state or the specific ADC 77 is always in operation. It can be said that it is more effective than the case where the remaining ADCs 77 are always in a non-operating state.

At the time of the image reading operation, since all of the ADCs 77 are in the operating state, it is possible to acquire an X-ray image of good image quality.

Embodiment 1-2
In the first and second embodiments shown in FIG. 18, the control unit 54 shifts the timing of switching the supply state of all the power of the first to sixteenth ADCs 77. That is, first, the first ADC 77 is put in an operating state for time T. After that, the second ADC 77 continues operating for time T, and the third ADC 77 continues operating for time T. After switching the power supply state to the sixteenth ADC 77 and bringing the sixteenth ADC into operation for time T, the first ADC 77 returns to the first ADC 77 again for being in operation T for time. Then, switching of the series of power supply states is repeated.

In this case, the read-out cycle of the dose signal DDS (C) is T × 16 = 16T, which takes longer than 4T in the first-first embodiment. However, since the number of operating ADCs 77 per unit time T is 1, the number per unit time T in the AED operation when the number 16 per unit time T in the image reading operation is standardized is 1/00. 16 = 0.0625, which can be further reduced than 0.25 of the above-described first embodiment.

Embodiment 1-3
FIG. 19 shows a first to third embodiment. Although the example in which three ADCs 77 are disposed between two ADCs 77 belonging to the same group has been described in the above first-first embodiment, as in the first to third embodiments, it is possible to use the same group There may not be one ADC 77 between the two belonging ADCs 77. In other words, two ADCs 77 belonging to the same group may be adjacent.

In FIG. 19, the first and second ADCs 77, the third and fourth ADCs 77, the fifth and sixth ADCs 77, the seventh and eighth ADCs 77,..., The thirteenth and fourteenth ADCs 77, and the fifteenth and sixteenth ADCs 77 They are groups to which the power supply state is switched at the same timing. However, there is no one ADC 77 between two ADCs 77 belonging to the same group, and they are adjacent to each other.

Embodiment 1-4
The first to fourth embodiments are shown in FIG. In the above embodiments, the power supply state of the ADC 77 is switched in area AR units. However, as in the first to fourth embodiments, the control unit 54 switches the power supply state of the ADC 77 in chip CP units. May be Specifically, first, the control unit 54 causes the first to fourth ADCs 77 of the chip CP1 to be in the operating state, and switches to the non-operating state after the time T has elapsed. Next, the fifth to eighth ADCs 77 of the chip CP2 are activated, and similarly switched to the inoperative state after the time T has elapsed. Subsequently, the ninth to twelfth ADCs 77 of the chip CP3 are put into operation for time T, and the thirteenth to sixteenth ADCs 77 of the chip CP4 are put into operation for time T. Then, switching of the series of power supply states is repeated.

As described above, if the power supply state of the ADC 77 is switched in chip CP units, control is easier than in the case of area AR units. In addition, it is possible to cope with a chip CP that does not have a function of switching the power supply state for each block BL.

[First to fifth embodiments]
The first to fifth embodiments are shown in FIG. In the above embodiments, the power supply states of all the ADCs 77 are switched periodically, but the present invention is not limited to this. As in the first to fifth embodiments, at least one ADC 77 may be always in a non-operating state.

In FIG. 21, in the first to fifth embodiments, even-numbered ADCs 77 such as the second, fourth, sixth,..., Sixteenth are always inactivated by the control unit 54 during AED operation. . On the other hand, in the odd numbered ADCs 77 such as the first, third, fifth,..., Fifteenth, the power supply state is periodically switched as in the above embodiments. As such, there may be an ADC 77 that is always disabled during AED operation. In the case of focusing on one ADC 77, power consumption can be reduced by switching the power supply state periodically if it is in a non-operating state at all times.

Note that, conversely to this, as in the image read operation, there may be an ADC 77 that is always operated during the AED operation (see FIG. 27). However, in this case, it is necessary for at least one ADC 77 to be deactivated during AED operation, either periodically or constantly. The reason is that if all the ADCs 77 are always in the operating state, they will be in the same state as in the image reading operation, and the number of operating states of the ADC 77 per unit time at the AED operation will be higher than in the image reading operation. It is because it is not reduced.

[1-6 embodiment]
FIGS. 22 and 23 show the first to sixth embodiments. In each of the above embodiments, for example, as in the first, fifth, ninth, and thirteenth ADCs 77 and the second, sixth, tenth, and fourteenth ADCs 77 of the first to eleventh embodiments shown in FIG. Although the other ADC 77 is switched from the non-operating state to the operating state at the timing when the operating state is switched from the operating state to the non-operating state, the present invention is not limited to this. As in the present 1-6 embodiment, the timing at which one ADC 77 is switched from the operating state to the non-operating state may be shifted from the timing at which the other ADC 77 is switched from the non-operating state to the operating state.

In FIG. 22, the first, fifth, ninth and thirteenth ADCs 77, second, sixth, tenth and fourteenth ADCs 77, third, seventh, eleventh and fifteenth ADCs 77, fourth, eighth and seventh The twelfth and sixteenth ADCs 77 are groups to which the power supply state is switched at the same timing, which is the same as the first to eleventh embodiments shown in FIG. However, while the first, fifth, ninth, and thirteenth ADCs 77 are in operation, specifically, the second, sixth, tenth, and fourteenth ADCs 77 can be activated at timing T / 2, or the like. Before switching the ADC 77 from the active state to the inactive state, the other ADC 77 is switched from the inactive state to the active state.

As described above, the reading period of the dose signal DDS (C) is shortened by shifting the timing of switching one ADC 77 from the operating state to the non-operating state and the timing of switching the other ADC 77 from the non-operating state to the operating state. be able to. Specifically, in the case of the above-described first embodiment, the reading cycle of the dose signal DDS (C) is 4T, but is short as 2.5T in FIG.

Also, in this case, the number of operating ADCs 77 per unit time T is that the four ADCs 77 are in the operating state for the time T and the four ADCs 77 are in the operating state for the time T / 2. , 4+ (4 × 0.5) = 6.

FIG. 22 is an example based on the above-described first embodiment shown in FIG. 14, but FIG. 23 shifts the timing of switching of the power supply state of all the first to sixteenth ADCs 77, This is an example based on the above first to second embodiments shown in FIG. Also in this case, as in the case of FIG. 22, before switching one ADC 77 from the operating state to the non-operating state, for example, the second ADC 77 is put into the operating state at the timing of T / 2 in the middle of the first ADC 77. , The other ADC 77 is switched from the non-operating state to the operating state. Also in this case, the reading cycle of the dose signal DDS (C) can be shortened from 16T to 8.5T in FIG. Further, the number of operating ADCs 77 per unit time T in this case is 1.5.

[First embodiment 1-7]
FIG. 24 shows a first embodiment 1-7. In the above embodiments, the timing of switching the power supply state of the plurality of ADCs 77 is shifted, but in the first to seventh embodiments, the control unit 54 supplies all the power states of the first to sixteenth ADCs 77. The timing of switching is the same.

In this case, the reading cycle of the dose signal DDS (C) is 2T obtained by adding the first half T in which all the ADCs 77 are in operation simultaneously and the second half time T in which all the ADCs 77 are inoperative simultaneously. . Also, the unit time in this case is not T but 2 T. The number of active ADCs 77 per unit time 2T is 16/2 = 8 because all 16 ADCs 77 are active during the first time T and none are active at the next time T. It is.

[First 1-8 embodiments]
FIGS. 25 to 27 show the 1-8th embodiment. In the above embodiments, during the AED operation, the dose signal DDS (C) based on the charges from all the pixels 40 is read out, so to say, all the pixels 40 are used as detection pixels for reading out the dose signal DDS (C). is working. However, some of the plurality of pixels 40 instead of all the pixels 40 may be set in advance as detection pixels. In the following, the detection pixel is given a code and denoted as a detection pixel 90 (see FIG. 25). Further, the signal line 42 to which the detection pixel 90 is connected is hereinafter referred to as a detection channel 95 (see FIG. 25).

FIG. 25 shows all the pixels 40 belonging to a total of eight areas AR covered by the chips CP2 and CP3 among the chips CP1 to CP4 as the detection pixels 90 (indicated by hatching). It is an example set. In this case, the detection channel 95 is the signal line 42 connected to the fifth to eighth MUX 76 of the chip CP2 and to the ninth to twelfth MUX 76 of the chip CP3.

For example, as shown in FIG. 26, the control unit 54 keeps the first to fourth ADCs 77 of the chip CP1 and the thirteenth to sixteenth ADCs 77 of the chip CP4 in a non-operating state at all times during AED operation. Do. Further, the control unit 54 periodically switches the power supply states of the fifth to eighth ADCs 77 of the chip CP2 and the ninth to twelfth ADCs 77 of the chip CP3 in charge of the detection channel 95.

When the detection channel 95 is set, the ADC 77 not in charge of the detection channel 95 has no meaning even if it is in the operating state at the time of the AED operation, and is always in the non-operating state during the AED operation. On the other hand, the power supply state of the ADC 77 in charge of the detection channel 95 is periodically switched during AED operation. This reduces the number of operating ADCs 77 per unit time T.

FIG. 27 is the same as the case of FIG. 26 in that the ADC 77 not in charge of the detection channel 95 is always inoperative during AED operation. However, in FIG. 27, the ADCs 77 (the fifth to eighth ADCs 77 of the chip CP2 and the ninth to twelfth ADCs 77 of the chip CP3) in charge of the detection channel 95 are always in the operating state. As can be understood from the example of FIG. 27, the first invention also includes the case where the power supply state of the ADC 77 is not switched periodically.

Although all the signal lines 42 of the areas AR5 to AR12 are set as the detection channel 95 in FIG. 25, for example, the first to fourth columns, the 65 to 68 columns, and the 129 to 132 columns. The detection channels 95 may be set at intervals of 64 columns, such as columns, in four columns, and the method of setting the detection channels 95 is free. In addition, the detection pixels 90 set in one detection channel 95 are not all the pixels 40 for one column, but, for example, the 481st to 960th lines that the third and fourth gate drive circuits 75 are in charge of There is no particular limitation on the setting method, such as setting only the pixel 40 of the pixel as the detection pixel 90.

[1-9 embodiment]
FIGS. 28 to 31 show the first to ninth embodiments. In each of the above embodiments, the pixel 40 for obtaining the image signal DIS (C) in the image reading operation is also used as the detection pixel 90 for obtaining the dose signal DDS (C) in the AED operation. Is not limited to this. Aside from the X-ray image detection pixels 40, dedicated detection pixels 90X specialized for the AED operation may be provided.

When the detection pixel 90X dedicated to the AED operation is provided, the pixel 40 and the detection pixel 90X are mixed on the light detection substrate 35. Since the size of the light detection substrate 35 is limited, if the detection pixels 90X are provided too much, the space for providing the pixels 40 is reduced accordingly, and the image quality of the X-ray image is degraded. In addition, when the detection pixel 90X is provided at a biased position on the light detection substrate 35, depending on the setting of the irradiation field, the case where the X-ray is not irradiated to the relevant position may be considered. Therefore, as shown in FIG. 28, for example, as shown in FIG. 28, the number of detection pixels 90X arranged in one row of detection channels 95 is 12 out of 2880, and the number of millions of pixels 40 is 40. On the other hand, it is preferable that the detection pixels 90X be on the order of several tens to several hundreds, and the detection pixels 90X be disposed on the light detection substrate 35 in a dispersed manner.

The basic configuration of the detection pixel 90X1 shown in FIG. 29 including the photoelectric conversion unit 43 and the TFT 44 is the same as that of the pixel 40. Therefore, the detection pixel 90X1 can be formed by substantially the same manufacturing process as the pixel 40. The detection pixel 90X1 is different from the pixel 40 in that the source electrode and the drain electrode of the TFT 44 are short-circuited by the short circuit line 100. That is, in the detection pixel 90X1 shown in FIG. 29, the photoelectric conversion unit 43 is directly connected to the signal line 42 by the short circuit line 100. This signal line 42 becomes a detection channel 95.

In the detection channel 95, the charge generated in the photoelectric conversion unit 43 of the detection pixel 90X1 flows out regardless of the on / off state of the TFT 44. Therefore, even if the pixels 40 in the same row are in the pixel charge accumulation operation with the TFT 44 turned off, charges generated in the photoelectric conversion unit 43 of the detection pixel 90X1 always flow into the CA 60 through the detection channel 95. Do.

Also in this case, as in the first to eighth embodiments shown in FIGS. 25 to 27, the ADC 77 not in charge of the detection channel 95 is always in a non-operating state during the AED operation. Further, the ADC 77 in charge of the detection channel 95 periodically switches the power supply state during the AED operation or is always in the operating state.

As a short-circuited pixel in which the photoelectric conversion unit 43 is directly connected to the signal line 42, the TFT 44 is removed as in the detection pixel 90X2 shown in FIG. 30, instead of the detection pixel 90X1 shown in FIG. It may be composed of only 43. In the example shown in FIGS. 29 and 30, the generated charges of the detection pixels 90X1 and 90X2 are always added to the generated charges of the pixels 40 in the same column as the detection pixels 90X1 and 90X2 which are short-circuited pixels. The pixels 40 in the same column as the detection pixels 90X1 and 90X2 can not be used as pixels for acquiring the image signal DIS (C). For this reason, the pixels 40 in the column of the detection channel 95 and the detection pixels 90X1 and 90X2 are treated as defective pixels, and are interpolated by the image signal DIS (C) of the pixels 40 in the column other than the surrounding detection channel 95.

FIG. 31 shows an example in which a detection pixel 90X3 dedicated to the AED operation is provided adjacent to a specific pixel 40. Similar to the pixel 40, the detection pixel 90X3 includes the photoelectric conversion unit 105 and the TFT 106. The TFT 106 is connected to a gate line 107 and a signal line (detection channel 95) different from the gate line 41 and the signal line 42 connected to the TFT 44 of the pixel 40. The gate line 107 is connected to a gate drive unit 108 which is driven independently of the gate drive unit 50. The detection channel 95 is connected to the MUX unit 62 together with the signal line 42.

During the AED operation, the gate driver 50 does not operate, and only the gate driver 108 operates. The gate driver 108 simultaneously applies gate pulses to the gate lines 107 in a plurality of rows, and turns on each of the TFTs 106 connected to the gate lines 107 in the same manner as in the first embodiment. Alternatively, the gate driver 108 may sequentially apply gate pulses to the gate lines 107.

Also in this case, as in the first to eighth embodiments shown in FIGS. 25 to 27, the ADC 77 not in charge of the detection channel 95 is always in a non-operating state during the AED operation. Further, the ADC 77 in charge of the detection channel 95 periodically switches the power supply state during the AED operation or is always in the operating state. The basic configuration of the MUX unit 62 is the same as that of each of the above-described embodiments, except that the detection channel 95 to which the detection pixel 90X3 is connected is also connected in addition to the signal line 42. Note that instead of providing a detection channel 95 separate from the signal line 42 exclusively for the detection pixel 90X3, the TFT 106 of the detection pixel 90X3 is also connected to the signal line 42, and the detection channel 95 is connected to the signal line 42. It may be shared.

In the case of FIG. 31, the pixel 40 and the detection pixel 90X3 can be driven independently of each other by the

gate drive units

50 and 108, and the signal line 42 and the detection channel 95 are separate. Therefore, as in the case of FIGS. 29 and 30, the pixels 40 in the same column as the detection pixels 90X3 may not be treated as defective pixels.

Embodiment 1-10
FIG. 32 shows an embodiment 1-10. In the first to tenth embodiments, the operator can change the setting of the detection pixels 90 that use the dose signal DDS (C) for the X-ray irradiation start determination among all the detection pixels 90. For example, in the case where the detection pixels 90X3 shown in FIG. 31 of the first to ninth embodiments are dispersedly disposed on the light detection substrate 35 as shown in FIG. 28, as shown in FIG. In this case, the detection pixel 90X3 in the rectangular area LA1 corresponding to the lung field of the patient P is selected, and the dose signal DDS (C) from the selected detection pixel 90X3 is used for X-ray irradiation start determination. On the other hand, in the case of abdominal imaging, the detection pixel 90X3 in the rectangular area LA2 is selected, and the dose signal DDS (C) from the selected detection pixel 90X3 is used for X-ray irradiation start determination.

In this case, the gate driving unit 108 has a function of selectively applying a gate pulse to the TFT 106 of the detection pixel 90X3 in the regions LA1 and LA2. When the detection pixel 90X3 in the area LA1 is selected in chest imaging, the signal line 42 of the range RLA1 corresponding to the width of the area LA1 serves as the detection channel 95. Therefore, the area RLA1 is in charge during AED operation. The power supply state of the ADC 77 is switched or kept in an operating state at all times. Then, the ADC 77 in charge of the other ranges RLA2 and RLA3 is inactivated. On the other hand, when the detection pixel 90X3 in the area LA2 is selected in the abdominal imaging, the power supply state of the ADC 77 in charge of the area RLA2 is switched or constantly operated during the AED operation. Then, in this case, the ADC 77 in charge of the ranges RLA1 and RLA3 is inactivated.

In FIG. 32, although the detection pixel 90X3 of FIG. 31 of the first to ninth embodiments is described as an example, the present invention is not limited to this. As in the first to eighth embodiments shown in FIG. 25 to FIG. 27, the pixel 40 for obtaining the image signal DIS (C) in the image readout operation and the dose signal DDS (C) for the AED operation. The same effect can be obtained by providing the gate driver 50 with a function of selectively applying the gate pulse G (R) to the TFTs 44 of the pixels 40 in the specific area also when the pixel 90 is also used as the detection pixel 90.

Also in the case of the detection pixels 90X1 and 90X2 shown in FIGS. 29 and 30 of the first to ninth embodiments, the detection pixels 90X1 and 90X2 are arranged only in the area LA1 in the range RLA1 and the area RLA2 If the detection pixels 90X1 and 90X2 are arranged only in LA2, the same effect can be obtained.

Embodiment 1-11
The first to eleventh embodiments are shown in FIGS. 33 and 34. As described above, the dose signal DDS (C) obtained in the AED operation is not used as image information of the patient P. Therefore, in the AED operation, the accuracy required for the image signal DIS (C) output in the image reading operation is not required for the dose signal DDS (C). Therefore, in the first to eleventh embodiments shown in FIG. 33, the power consumption of the signal processing circuit 51 in the AED operation is further reduced by simplifying the operation of the CDS 61 in the AED operation as compared with the image reading operation.

The operation of the CDS 61 at the time of image reading, the outline of which has been described with reference to FIG. 6, is as shown in FIG. That is, the reset noise component is held by the first S / H 73A of the CDS 61 (step ST300). Then, the analog voltage signal V (C) is held at the second S / H 73B (step ST310). Finally, the difference between the reset noise component held in both S /

Hs

73A and 73B and the analog voltage signal V (C) is taken by the differential amplifier 74, and the analog voltage signal V (C) from which the noise has been removed is calculated. It outputs (step ST320).

On the other hand, during the AED operation, as shown in FIG. 33B, the holding of the reset noise component by the first S / H 73A in step ST300 is skipped, and the holding of the analog voltage signal V (C) by the second S / H 73B in step ST310. Begin. Then, the analog voltage signal V (C) is output as it is from the differential amplifier 74 without taking the difference with the reset noise component (step ST330).

As described above, since the retention of the reset noise component by the first S / H 73A is skipped during the AED operation, power supply to the first S / H 73A is unnecessary, or the first S / H 73A is driven with lower power than the image reading operation. It becomes possible. Therefore, the power consumption of the signal processing circuit 51 during the AED operation can be further reduced. Further, since the retention of the reset noise component by the first S / H 73A is skipped, the AED operation can output the analog voltage signal V (C) faster than the image reading operation.

Although the differential amplifier 74 is connected to the input terminal of the MUX 76 as shown in FIG. 6 in the above first embodiment, the present invention is not limited to this. As shown in FIG. 34, two

MUXs

76A and 76B are connected between the first and second S /

Hs

73A and 73B and the differential amplifier 74, and the differential amplifier 74 is connected between the

MUXs

76A and 76B and the ADC 77. May be.

In this case, for example, the first S / Hs 73A of the plurality of CDS 61 in the same area AR column are connected to the MUX 76A, and the second S / H 73B is connected to the MUX 76B. Further, in the above first-first embodiment, as shown in FIG. 6, the differential amplifier 74 is connected to the front stage of the MUX 76, so the differential amplifier 74 is provided for each CDS 61. Since the differential amplifiers 74 are connected to the subsequent stages of the

MUXs

76A and 76B, the differential amplifiers 74 have the same number as the ADCs 77.

Also in the configuration shown in FIG. 34, power saving can be achieved by skipping retention of the reset noise component by the first S / H 73A during the AED operation as shown in FIG. 33B. Furthermore, in this case, the power supplied to the MUX 76A can be reduced in addition to the first S / H 73A, and further, the power supplied to the differential amplifier 74 can be reduced by reducing the number of differential amplifiers 74. it can. Therefore, the power consumption of the signal processing circuit 51 during the AED operation can be further reduced.

[Embodiments 1-12]
FIGS. 35 to 37 show the first to twelfth embodiments. Here, for example, as in the seventh ADC 77 shown in FIG. 18 of the above-described first and second embodiments, the timing of switching of the power supply state is in the inactive state for the sixth and eighth ADCs 77 on both sides for a relatively long time. If they are different, the temperature distribution in the column direction of the block BL7 when the ADC 77 is in the operating state is as shown in FIG. That is, the temperature drops due to the influence of the non-operating blocks BL6 and BL8 at both ends by all means, resulting in a mountain-shaped temperature distribution in which the temperature at the central portion is higher than this. The temperature distribution of the block BL6 has a gentle mountain shape because, as shown in FIG. 18, the sixth ADC 77 is put into operation immediately before the seventh ADC 77 is put into operation.

The change in the temperature distribution in the block BL is gradual since the central portion approaches a flat and becomes gentle since the width in the column direction of the block BL is wide when the number of columns of the pixels 40 in charge in the block BL is large. On the other hand, when the number of columns of the pixels 40 in charge of the block BL is small, the width in the column direction of the block BL becomes narrow, and therefore, it becomes steep. As described above, when there is a temperature distribution deviation in the block BL, a temperature drift occurs in the digital signal DS (C). In order to minimize the influence of the temperature drift, the detection channel 95 having the detection pixel 90 is preferably disposed at the center of the area AR where the temperature gradient tends to be relatively flat.

In the example shown in FIGS. 29 and 30 of the first to ninth embodiments, the number of detection pixels 90X1 and 90X2 arranged in one row of detection channels 95 is, for example, 12 out of 2880, or the like. Less than 1% of As described above, the number of pixels 40 and the number of detection pixels 90X1 and 90X2 is in the relation of the pixel 40 >> detection pixels 90X1 and 90X2.

Here, the charge generated in the pixel 40 flows into the signal line 42 although the amount is small even if the TFT 44 is in the off state. Such charge is called leak charge. In the detection channel 95 of the example shown in FIGS. 29 and 30, in addition to the charge SC generated in the detection pixels 90X1 and 90X2, this leak charge LC also flows, as schematically shown in FIG. . Since the leak charge LC is added to the charge SC generated in the detection pixels 90X1 and 90X2 which are originally to be extracted as the dose signal DDS (C), it becomes noise when determining the start of X-ray irradiation. Moreover, when the relationship of the pixel 40 >> detection pixels 90X1 and 90X2 is satisfied, the amount of the leak charge LC becomes an unignorable amount with respect to the charge SC generated in the detection pixels 90X1 and 90X2. There is an increased risk of misjudgement of the start of irradiation. Therefore, in the first to twelfth embodiments, the influence of the leak charge LC is removed from the dose signal DDS (C) of the detection channel 95, and then the correction of removing the influence of the temperature drift is performed.

Specifically, as shown in FIG. 37, a pixel 40 not including the detection pixels 90X1 and 90X2 so as to sandwich the detection channel 95 adjacent to the detection channel 95 in which the detection pixels 90X1 and 90X2 are arranged. Provide a row of only. Hereinafter, the signal line 42 corresponding to the row of only the pixels 40 not including the detection pixels 90X1 and 90X2 is expressed as a reference channel 120.

In FIG. 37, the detection channel 95 and the reference channel 120 are connected to the same MUX 76 and ADC 77. That is, the detection channel 95 and the reference channel 120 are in the same block BL. In this case, the control unit 54 causes the ADC 77, which is in charge of both the detection channel 95 and the reference channel 120, to be in an active state during the AED operation. When the detection channel 95 and the reference channel 120 are divided into different blocks BL and connected to different ADCs 77, the control unit 54 causes the ADC 77 in charge of the detection channel 95 to be in the operating state and the reference channel 120. The ADC 77 responsible for the

Thus, the memory 52 stores the dose signal DDS (C) based on the analog voltage signal V (C) from the detection channel 95 and the analog voltage signals V (C-1) and V (C) from the reference channel 120. Dose signals DDS (C-1) and DDS (C + 1) based on C + 1) are output from the ADC 77. The dose signals DDS (C-1) and DDS (C + 1) are hereinafter referred to as reference signals DRS (C-1) and DRS (C + 1).

Leakage charge correction unit 121 accesses memory 52 and reads out dose signal DDS (C) from memory 52. The leak charge correction unit 121 is provided, for example, in the control unit 54. The leak charge correction unit 121 performs subtraction shown in the following equation (1) to obtain a leak charge corrected dose signal RCDDS (C) from the dose signal DDS (C).
RCDDS (C) = DDS (C)-DRS (C) (1)
Where DRS (C) = {DRS (C-1) + DRS (C + 1)} / 2
That is, the leak charge corrected dose signal RCDDS (C) is obtained from the dose signal DDS (C) from the detection channel 95 to the two reference signals DRS (C-1) and DRS (C + 1) from the reference channel 120 in two columns. The average value of DRS (C) is subtracted.

The reference signals DRS (C−1) and DRS (C + 1) are components based on the leak charge LC of the pixel 40 connected to the reference channel 120. The detection channel 95 and the reference channel 120 are adjacent to each other, and the number of pixels 40 is almost the same. Therefore, the average value DRS (C) of the reference signals DRS (C-1) and DRS (C + 1) is the detection channel It is considered to be substantially coincident with the component based on the leak charge LC of the pixel 40 connected to 95. Therefore, the component of the leak charge LC can be removed from the dose signal DDS (C) by performing the subtraction of the above equation (1).

A temperature drift correction unit 122 is provided downstream of the leak charge correction unit 121. The temperature drift correction unit 122 is provided, for example, in the control unit 54 as the leak charge correction unit 121 is. The temperature drift correction unit 122 multiplies the leakage charge corrected dose signal RCDDS (C) by the correction coefficient α (C) as shown in the following equation (2) to obtain a temperature drift corrected dose signal DRCDDS (C) and Do.
DRCDDS (C) = RCDDS (C) x α (C) (2)

The temperature distribution shown in FIG. 35 in the signal processing circuit 51 including the detection channel 95 and the reference channel 120 is reflected in the reference signals DRS (C−1) and DRS (C + 1). That is, according to the reference signals DRS (C-1) and DRS (C + 1), it can be known how much temperature drift is occurring in the dose signal DDS (C). The correction coefficient α (C) is obtained from the calculation formula F {DRS (C−1), DRS (C + 1)} using the reference signals DRS (C−1) and DRS (C + 1) as variables. The correction coefficient α (C) is the standard condition when all the ADCs 77 are in operation in the image reading operation and each block BL 1 to 16 is in thermal equilibrium condition, and the leak charge corrected dose signal RCDDS (C) is in the standard condition. This coefficient is the same value as when read. The correction coefficient α (C) is obtained for each of the detection channels 95. Note that the correction coefficient α (C) may be obtained from a calculation formula in which the average value DRS (C) of the reference signals DRS (C−1) and DRS (C + 1) is a variable.

There is a chip CP on which a temperature measurement function for measuring the temperature TP of the central portion of each block BL is mounted in advance. In this case, the correction coefficient α (C) is determined based on the temperature TP acquired by the temperature measurement function (using a calculation formula with the temperature TP as a variable). If the chip CP does not have a temperature measurement function, another temperature measurement function may be provided to obtain the temperature TP from there.

When it is determined that temperature drift does not occur in the dose signal DDS (C), for example, when the temperature TP is in the standard state, the temperature drift correction unit 122 may not perform correction of the temperature drift. Specifically, a threshold is set to the temperature TP, and the temperature drift is not corrected when the temperature TP is equal to or less than the threshold, and the temperature drift is corrected when the temperature TP is higher than the threshold.

At the time of image reading operation, since all ADCs 77 are always in the operating state, the temperature distribution as shown in FIG. 35 is unlikely to be uneven, but of course the temperature drift correction unit 122 also performs the image signal DIS (C). Correction of temperature drift may be performed.

When the power supply state of the ADC 77 is switched in chip CP units as in the first to fourth embodiments shown in FIG. 20, the temperature distribution bias shown in FIG. 35 is not in block BL units but in chip CP units. It occurs. Therefore, in this case, the temperature TP is measured in chip CP units, and the temperature drift is corrected in chip CP units.

When switching the power supply state of the ADC 77 per chip CP, take measures to prevent the temperature distribution itself from being biased, for example, connecting adjacent chips CP with a heat conduction member such as a heat sink or heat pipe Is preferred.

Note that, in FIG. 37, the reference channel 120 is one adjacent row (two rows in total) sandwiching the detection channel 95, but may be a plurality of rows. Preferably, two rows or more (four rows in all) are preferable. That is, when the number of reference channels 120 is small and the number of reference signals is small, the average value DRS of the reference signals to be subtracted from the dose signal DDS (C) when the value of the reference signal varies in each reference channel 120 It is because the reliability of (C) becomes low.

In the case of the detection pixel 90X3 shown in FIG. 31 of the first to ninth embodiments, the signal line 42 and the detection channel 95 are separate, and the pixel 40 is not connected to the detection channel 95. The leak charge LC of the pixel 40 does not flow into the channel 95. Also in the case where the detection channel 95 and the signal line 42 are also used in FIG. 31, the generated charge of the detection pixel 90X3 does not flow into the signal line 42 if the TFT 106 is turned off. Therefore, when the TFT 106 is in the off state, the signal line 42 used also as the detection channel 95 behaves as if it is the reference channel 120. Therefore, in this case, the digital signal DS (C) read out with the TFT 106 turned off may be replaced with the reference signal, and subtracted from the dose signal DDS (C) read out with the TFT 106 turned on. That is, in any case, in the case of FIG. 31, it is not necessary to provide a dedicated reference channel 120.

[First embodiment 1-13]
In the first to thirteenth embodiments shown in FIG. 38, in the AED operation, the control unit 54 performs an image reading operation on an interface (hereinafter referred to as I / F (Interface)) that transmits the digital signal DS (C) in the subsequent stage of the ADC 77. Switch to the one with lower power consumption than time. Thus, the power consumption of the signal processing circuit 51 during the AED operation may be reduced.

In FIG. 38, two types of LVDS (Low Voltage Differential Signaling) I / F 125 and CMOS I / F 126 are prepared for transmission I / F of digital signal DS (C) between ADC 77 and memory 52. The LVDS I / F 125 has higher transmission accuracy than the CMOS I / F 126, but consumes more power than the CMOS I / F 126. The control unit 54 controls the operation of the switch 127 to switch these transmission I / Fs.

FIG. 38A shows the AED operation time, and FIG. 38B shows the image reading operation time. That is, the CMOS I / F 126 is selected in the AED operation, and the LVDS I / F 125 is selected in the image read operation.

As described above, since the CMOS I / F 126 is selected in the AED operation, it is possible to further reduce the power consumed by the signal processing circuit 51 in the AED operation. Although the accuracy of the transmission of the dose signal DDS (C) is low, the dose signal DDS (C) is not used as image information of the patient P, so even if there is a slight error in the transmission, this is not a major problem. On the other hand, since the LVDS I / F 125 is selected at the time of the image reading operation, the power consumption increases, but the image signal DIS (C) can be accurately transmitted to the memory 52.

The transmission I / F of the digital signal DS (C) between the ADC 77 and the memory 52 may be only the CMOS I / F 126, and the voltage supplied to the CMOS I / F 126 may be switched. For example, the supply voltage is set to 5.0 V at the time of image reading operation and 3.3 V at the time of AED operation. Alternatively, it may be 2.5 V at the time of image reading operation and 1.8 V at the time of AED operation. The higher the supply voltage, the wider the dynamic range and the more accurate the transmission, but the higher the power consumption, the lower the supply voltage during AED operation than during image readout operation. As a result, the power consumed by the signal processing circuit 51 in the AED operation can be further reduced.

In each of the above embodiments, the second state is illustrated as the non-operating state. As described above, the non-operating state includes the state in which the power PSL_A is supplied, the power-off state in which no power is supplied to the ADC 77, and the state in which the clock signal supply to the ADC 77 is stopped. However, the second state is not limited to such a non-operating state. For example, the number of pulses per unit time of the clock signal to the ADC 77 may be reduced as compared to the first state, and the power consumption per unit time of the ADC 77 may be reduced as compared to the first state as the second state.

2. Second Invention In the second invention shown in FIGS. 39 to 43 described below, the control unit 54 is a non-detection channel 130 (see FIG. 39A) which is a signal line 42 other than the detection channel 95 among the plurality of CAs 60. Supply non-detecting CA 131 (see FIG. 39A) connected to at least one of the non-detecting CAs 131 (see FIG. 39A) in a power saving state lower than the normal power in the image reading operation. It is the content. As a result, the power supplied to the CA 60 including the non-detection CA 131 during the AED operation is reduced as compared to that during the image read operation.

In the second invention, basic configurations of the X-ray imaging system 10, the electronic cassette 16 and the like are the same as those of the first invention described above. Also, the patterns exemplified in the above 1-1 to 1-7 embodiments can be applied to the switching pattern of the power supply state of the ADC 77. Furthermore, a combination with other embodiments of the first invention (the above 1-8 to 1-13 embodiments) is also possible. Hereinafter, the same parts as those of the first invention are given the same reference numerals, and the description thereof is omitted, and the differences will be mainly described.

Embodiment 2-1
FIGS. 39 and 40 show a 2-1 embodiment. In the present second embodiment, for example, a configuration including the detection pixel 90X1 shown in FIG. 29 of the first to ninth embodiments or the detection pixel 90X2 shown in FIG. 30 will be described. However, the configuration is not limited to this.

In the present second embodiment, as shown in FIG. 39A, in order to simplify the description, the odd channel of 1 row, 3 columns, 5 columns,. The case where even-numbered columns of four columns, six columns,..., 144 columns are the non-detection channel 130 is illustrated. Hereinafter, the CA 60 connected to the detection channel 95 is referred to as a detection CA 132 in order to distinguish it from the non-detection CA 131 which is the CA 60 connected to the non-detection channel 130. The alphabet DT at the top of the detection channel 95 indicates that the column is the detection channel 95, and the alphabet NDT at the top of the non-detection channel 130 indicates that the column is the non-detection channel 130. It shows.

The MUX 76 sequentially selects the analog voltage signals V (C) from the plurality of CAs 60 and outputs the selected analog voltage signal V (C) to the ADC 77, as in the above embodiments.

In the present second embodiment, as shown in FIG. 39B, the supplied power P_C to the CA 60 during AED operation is PN_C in the case of CA 132 for detection and PL_C lower than PN_C in the case of CA 131 for non-detection. Do. The supplied power PN_C is power supplied to all the CAs 60 at the time of image reading operation, and corresponds to normal power. The supplied power PL_C to the non-detection CA 131 is, for example, a value 1/10 of the normal power PN_C. That is, the state of non-detection CA 131 shown in FIG. 39B is a low power state in which power PL_C lower than normal power PN_C and larger than 0 is supplied.

As described above, since only the supply power PL_C lower than the normal power PN_C is supplied to the non-detection CA 131, the digital signal DS (C) based on the analog voltage signal V (C) from the non-detection CA 131 is The data is meaningless. Therefore, as shown in FIG. 39A, the control unit 54 does not use the digital signal DS (C) based on the analog voltage signal V (C) from the non-detection CA 131 as the dose signal DDS (C). Destroy

FIG. 40 is a flowchart showing the operation procedure of the electronic cassette of the present second embodiment. The difference between the flowchart shown in FIG. 17 of the first-first embodiment and the flowchart shown in FIG. 17 is step ST1202 and step ST1802 surrounded by a dashed dotted line. Only the differences will be described below.

In step ST1202, in the AED operation, the power supplied to the detection CA 132 is the normal power PN_C, and the power supplied to the non-detection CA 131 is PL_C lower than PN_C (irradiation start detection step). In step ST1802, in the image reading operation, the power supplied to all the CAs 60 is set as the normal power PN_C regardless of the detection CA 132 and the non-detection CA 131 (image reading step).

As described above, since the power supplied to the non-detection CA 131 during the AED operation is set to the power saving state lower than the normal power, the power consumed by the signal processing circuit 51 in the AED operation can be reduced. Therefore, as in the first aspect of the invention, the battery 65 lasts longer than in the prior art, and the number of times the battery 65 is charged is also reduced, so that the imaging efficiency can be improved.

Note that the non-detection CA 131 to be in the power saving state during the AED operation may be at least one of all the non-detection CAs 131. Of course, it is preferable to set all the non-detection CAs 131 in the power saving state in order to exert the maximum effect.

Embodiment 2-2
A second embodiment is shown in FIG. 39 and 40, the supplied power PL_C to the non-detection CA 131 during the AED operation is set to a value larger than 0. However, in the 2-2 embodiment, FIG. As shown, the supply power PL_C to the non-detection CA 131 during AED operation is set to 0. That is, the non-detection CA 131 is brought into the power-off state in which the supply of power is stopped.

As described above, when the non-detection CA 131 is in the power-off state, the power supplied to the non-detection CA 131 is 0, which is different from the case of the above-described second embodiment shown in FIGS. 39 and 40. Furthermore, the power consumption of the non-detection CA 131 can be reduced.

However, when the non-detection CA 131 is in the power-off state, the virtual short state between the two input terminals of the non-detection CA 131 can not be maintained, and the potential of the input stage of the non-detection CA 131 becomes unstable. As a result, the charge of the non-detection channel 130 also becomes unstable, which adversely affects the later image reading operation. For this reason, as in the case of the second embodiment, the power for supplying the non-detection CA 131 is completely 0 and the power-off state is set as in the case of the second embodiment. It is more preferable to supply the supply power PL_C to such an extent that the potential of the input stage of the CA 131 does not become unstable to make the power state low.

When the non-detection CA 131 is in the power-off state, measures such as shown in FIG. 42 may be taken to prevent the image reading operation from being adversely affected. That is, the switch 133 whose opening and closing is controlled by the control unit 54 is provided at the front stage of the non-detection CA 131. Then, during the AED operation shown in FIG. 41A in which the supplied electric power is 0, the control unit 54 turns off the switch 133 to disconnect the non-detection CA 131 and the non-detection channel 130 from each other. Furthermore, the control unit 54 supplies the non-detection CA 131 with the same reference potential as when the normal power PN_C is supplied. On the other hand, the switch 133 is turned on at the time of the image reading operation in which the normal power PN_C shown in FIG. 41B is supplied. In this case, although there is a need to provide the switch 133, the influence of the charge instability of the non-detection channel 130 due to the potential of the input stage of the non-detection CA 131 becoming unstable is an image reading operation. It never happens.

Also in this case, as in the above-described second embodiment, the non-detection CA 131 to be in the power-off state at the time of AED operation may be at least one of all non-detection CAs 131. From the viewpoint, it is more preferable that all the non-detection CAs 131 be in the power-off state.

Embodiment 2-3
In the second to third embodiments shown in FIG. 43, not only the non-detection CA 131 but also the detection CA 132 are driven in a low power state in which power lower than the normal power PN_C and larger than 0 is supplied. Specifically, the power supplied to the non-detection CA 131 during AED operation is PL_C1 which is 1/10 of the normal power PN_C, and the power supplied to the detection CA 132 is PL_C2 which is 1⁄2 of the normal power PN_C. Do. The transient response characteristic of the detection CA 132 is degraded by the half of the normal power PN_C. In this case, the operating speed of the ADC 77 is delayed to compensate for the degradation of the transient response characteristic. Then, there is no problem because a dose signal DDS (C) that is meaningful in data can be obtained. Since the power supplied to the detection CA 132 is also reduced in addition to the non-detection CA 131, the power consumption of the signal processing circuit 51 during the AED operation can be further reduced.

In the second to third embodiments, as in the case of the non-detection CA 131 of each of the above-described embodiments, the detection CA 132 to be in the low power state at the time of AED operation is at least one of all the detection CAs 132. However, it is more preferable to set all the detection CAs 132 in the low power state from the viewpoint of power consumption reduction.

As described above, each embodiment of the second invention may be implemented in combination with each embodiment of the first invention. For example, as shown in FIG. 14 and the like of the first-first embodiment, the control unit 54 supplies power of the ADC 77 and the MUX 76 that configures the block BL with this to the first state and the second state. It may be switched periodically. In this case, the first state is, for example, the above-described operating state, in which power necessary to perform the functions of the MUX 76 and the ADC 77 is supplied to each. On the other hand, the second state is, for example, the above-mentioned non-operating state, in which power that can not perform a function is supplied to at least one of MUX 76 and ADC 77, or a clock signal is supplied to ADC 77. It has not been done. Furthermore, the second state includes a state in which the number of pulses per unit time of the clock signal to the ADC 77 is reduced compared to the first state.

For the combination of the ADC 77 of the second invention and the above-described first invention, and further the switching pattern of the power supply of the block BL, for example, the combination shown below is possible. First, as shown in FIG. 14 and the like of the first-first embodiment, when there are two or more blocks 76 of the MUX 76 and the ADC 77 that periodically switch the power supply state, the control unit 54 The timing of switching of the power supply state of at least two blocks BL in the block BL may be shifted.

Furthermore, as shown in FIG. 14 and the like of the first-first embodiment, the timing of switching of the power supply state may be shifted for each of a plurality of groups to which two or more blocks BL belong. In this case, preferably, at least one block BL is disposed between two blocks BL belonging to the same group. Alternatively, as shown in FIG. 18 and the like of the first and second embodiments, the timing of switching the supply state of all the power of two or more blocks BL may be shifted.

As shown in FIG. 21 and the like of the first to fifth embodiments, when there are a plurality of blocks BL including the MUX 76 to which only the non-detection CA 131 is connected, at least one of them is always kept in the second state. May be

Leakage charge correction and temperature drift correction may be applied to the dose signal DDS (C) as shown in the first to twelfth embodiments of FIGS.

Besides, the above-described first to eighth embodiments in which the detection channel 95 which is the signal line 42 to which the detection pixel 90 used for the AED operation shown in FIGS. 25 to 27 is connected are set. The first to ninth embodiments shown in FIG. 31, provided with detection pixels 90X dedicated to the AED operation, the above first to tenth embodiments shown in FIG. 32, in which the detection pixels 90 can be changed, FIG. 33 and FIG. The first to eleventh embodiments for simplifying the operation of the CDS 61 during the AED operation shown in FIG. 34 and the above first to thirteenth embodiments for switching the transmission I / F of the digital signal shown in FIG. 38 may be combined.

3. Third Invention In the third invention shown in FIGS. 44 to 49 described below, the control unit 54 selectively transmits the analog voltage signal V (C) from a part of CA including the detection CA 132 to the ADC 77. Output and the ADC 77 performs only AD conversion processing on the selectively output analog voltage signal V (C), and the number of pulses per unit time of the clock signal of the ADC 77 during AED operation , The content is reduced compared to the image reading operation.

In the third invention, as in the second invention, the basic configurations of the X-ray imaging system 10, the electronic cassette 16 and the like are the same as those of the first invention described above. Also, the patterns exemplified in the above 1-1 to 1-7 embodiments can be applied to the switching pattern of the power supply state of the ADC 77. Furthermore, combinations with other embodiments of the first invention (the above 1-8 to 1-13 embodiments) and the above-mentioned 2-1 to 2-3 embodiments of the second invention are also possible. Hereinafter, the same parts as those of the first invention and the second invention are denoted by the same reference numerals, and the description thereof is omitted, and the differences will be mainly described.

Embodiment 3-1
FIGS. 44 to 48 show a third embodiment. In the present third embodiment, as in the above second embodiment, for example, a configuration including the detection pixel 90X1 shown in FIG. 29 of the above first embodiment or the detection pixel 90X2 shown in FIG. However, the configuration is not limited to this.

FIG. 44 shows the procedure for reading out the dose signal DDS (C) of the area AR1 in the first to 144th columns, as in FIG. In FIG. 44, as in FIG. 39A, the odd channel of 1 column, 3 columns, 5 columns,..., 143 columns is the

detection channel

95, and 2 columns, 4 columns, 6 columns,. The case where even-numbered columns are non-detection channels 130 is illustrated.

In this case, the difference from FIG. 39A is that MUX 76 is changed to MUX 135. The MUX 76 has only the function of sequentially selecting one column at a time. On the other hand, the MUX 135 has a function of sequentially selecting the analog voltage signal V (C) from the detection CA 132 of the detection channel 95 of the odd number column by skipping the non detection channel 130 of the even number column. That is, the MUX 135 has a function of selecting an analog voltage signal V (C) from a part of the plurality of connected CAs 60, in this case, the detection CA 132 of the detection channel 95. This function can be realized by providing a switch or the like in the flip flop circuit of the shift register constituting the MUX 135.

In the reading procedure of the dose signal DDS (C), first, as shown in FIG. 44A, the first MUX 135 selects the analog voltage signal V (1) in the first column. As a result, the analog voltage signal V (1) is input to the first ADC 77, and is converted into the dose signal DDS (1) by the first ADC 77. Next, as shown in FIG. 44B, the analog voltage signal V (2) in the second column is skipped, and the first MUX 135 selects the analog voltage signal V (3) in the third column. As a result, the analog voltage signal V (3) is input to the first ADC 77, and is converted into the dose signal DDS (3) by the first ADC 77. Subsequently, as shown in FIG. 44C, the first MUX 135 selects the analog voltage signal V (5) in the fifth column. Accordingly, the analog voltage signal V (5) is input to the first ADC 77, and is converted into the dose signal DDS (5) by the first ADC 77.

Such a series of operations are repeated by the first MUX 76 and the first ADC 77, and finally, as shown in FIG. 44D, the analog voltage signal V (143) of the 143rd column is converted to the dose signal DDS (143) Thus, the reading of the dose signals DDS (1), DDS (3), DDS (5),..., DDS (143) of the area AR1 is completed. The same applies to each MUX 135 and each ADC 77 of the other areas AR2 to AR16.

As described above, the image signals DIS (C) of all the columns are read out during the image reading operation, while only the dose signals DDS (C) of the odd columns are selectively read out during the AED operation. The number of digital signals DS (C) that must be reduced to 1/2 during AED operation compared to image reading operation. During this AED operation, if the dose signal DDS (C) whose number is reduced to 1/2 is read out in the same time as the image reading operation for reading the image signals DIS (C) of all the columns, the operating speed of the ADC 77 Can be slowed down.

Specifically, as shown in FIG. 45, the pulse number NPU_A of the clock signal of the ADC 77 per unit time, the normal pulse number NPUN_A at the time of image readout operation, and NPUL_A of 1⁄2 of NPUN_A at the time of AED operation Do.

There are two ways to set the number of pulses per unit time of the clock signal of the ADC 77 to NPUL_A which is 1/2 of NPUN_A at the time of image reading operation. The first method is shown in FIG. FIG. 46A shows the clock signal CLN_A at the time of image reading operation, and FIG. 46B shows the clock signal CLL_A at the time of AED operation.

In FIG. 46, the period TC of the clock signal itself is the same between the clock signal CLN_A at the time of the image reading operation and the clock signal CLL_A at the time of the AED operation. However, while the clock signal CLN_A is continuously and continuously issued regardless of the detection channel 95 and the non-detection channel 130, the clock signal CLL_A corresponds to the detection channel 95 of the odd-numbered column. Only the part is emitted, and the part corresponding to the non-detection channel 130 in the even number row is paused without being emitted.

In the example of FIG. 46, the unit time T is a period required for the output of the digital signal DS (C) of two adjacent columns. As described above, since the clock signal CLL_A is paused at the portion corresponding to the non-detection channel 130 in the even-numbered column among the two adjacent columns, the number of pulses per unit time T is one clock signal CLN_A. It will be / 2.

A second method of setting the number of pulses per unit time of the clock signal of the ADC 77 to NPUL_A which is 1/2 of NPUN_A at the time of image reading operation is shown in FIG. Similarly to FIG. 46, FIG. 47A shows a clock signal CLN_A at the time of image reading operation, and FIG. 47B shows a clock signal CLL_A at the time of AED operation. The clock signal CLN_A at the time of the image reading operation is exactly the same as the case of FIG. On the other hand, the clock signal CLL_A at the time of AED operation is not provided with a pause period as shown in FIG. 46B, and instead, the cycle of CLL_A is twice as long as 2TC with respect to the cycle TC of the clock signal CLN_A. .

In the example of FIG. 47, the unit time T is a cycle 2TC of the clock signal CLL_A. In the cycle 2TC, the number of pulses of the clock signal CLN_A is two, while the number of pulses of the clock signal CLL_A is one. Therefore, the number of pulses per unit time T of the clock signal CLN_A is 1⁄2 of the clock signal CLN_A as in the case of FIG.

FIG. 48 is a flowchart showing the operation procedure of the electronic cassette of the present 3-1 embodiment. The difference between the flowchart shown in FIG. 17 of the first-first embodiment and the flowchart shown in FIG. 17 is step ST1203 and step ST1803 surrounded by an alternate long and short dash line. Only the differences will be described below.

In step ST1203, in the AED operation, the analog voltage signal V (C) from the detection CA 132 is selectively output to the ADC 77, and the analog voltage signal V (C Only the AD conversion process for Then, the number of pulses per unit time T of the clock signal of the ADC 77 is reduced compared to that at the time of the image reading operation (irradiation start detection step). In step ST1803, the number of pulses per unit time T of the clock signal of the ADC 77 is set as the normal number of pulses (NPUN_A) in the image reading operation (image reading step).

As described above, since the number of pulses per unit time T of the clock signal of the ADC 77 at the time of AED operation is reduced compared to that at the time of the image reading operation, power consumption for driving the ADC 77 at the time of AED operation can be reduced. As a result, the power consumption of the signal processing circuit 51 during the AED operation can be reduced. Therefore, as in the first and second aspects of the invention, the battery 65 lasts longer than in the prior art, thereby reducing the number of times the battery 65 is charged, so that the imaging efficiency can be improved.

In FIG. 44, for convenience of explanation, a half row of one area AR is used as the detection channel 95, but as described in the first to eighth embodiments, the method of setting the detection channel 95 Is free.

Embodiment 3-2
A third embodiment is shown in FIG. In the above-described 3-1 embodiment, the MUX 135 having a function of selecting the analog voltage signal V (C) from a part of the plurality of connected CAs 60 is used. However, when the MUX 135 having such a function does not exist as a general-purpose product, for example, the MUX 76 having only the function of sequentially selecting one row at a time is modified to make the MUX 135, or the MUX 135 having the above function is custom-made It takes time and money. Therefore, in the third-2 embodiment shown in FIG. 49, the analog voltage signal V (C) from a part of CA is selectively output to the ADC 76 while using the general MUX 76.

FIG. 49 shows a circuit configuration of the detection channel 95 in the present third embodiment. The detection channel 95 is divided into a first path 140 connected to the MUX 76 and a second path 141 connected to the ADC 77 without the MUX 76 at a stage subsequent to the CDS 61. The first path 140 is a path that outputs the analog voltage signal V (C) from the detection CA 132 to the ADC 77 via the MUX 76. On the other hand, the second path 141 is a path for outputting the analog voltage signal V (C) to the ADC 77 without passing through the MUX 76.

A switch 142 is connected to the detection channel 95, the first path 140, and the second path 141. The control unit 54 controls the drive of the switch 142 to switch the path connected to the detection channel 95 between the first path 140 and the second path 141.

FIG. 49A shows the AED operation time, and FIG. 49B shows the image reading operation time. That is, the second path 141 is selected by the switch 142 during the AED operation, and the first path 140 is selected during the image reading operation.

Thus, the first channel 140 for outputting the analog voltage signal V (C) from the detection CA 132 to the ADC 77 via the MUX 76 and the detection channel 95 from the detection CA 132 without passing through the MUX 76. The analog voltage signal V (C) is divided into a second path 141 for outputting to the ADC 77. Then, at the time of the AED operation, the switch 142 is controlled to select the second path 141. Therefore, it is not necessary to prepare a special MUX 135 as in the above-described third embodiment shown in FIG. 44, and it is possible to save time and effort.

As described above, each embodiment of the third invention may be implemented in combination with each embodiment of the first invention and the second invention. For example, as in the case of the second invention, as shown in FIG. 14 and the like of the first-first embodiment by applying the first invention, the controller 54 controls the ADC 77 and the block BL. The power supply state of the MUX 76 may be switched periodically between the first state and the second state. The definitions of the first state and the second state are as described at the end of the second invention.

Similar to the second aspect of the invention, the combination of the third aspect of the invention and the ADC 77 of the first aspect of the invention and the switching pattern of the power supply of the block BL can be, for example, the following combination. First, as shown in FIG. 14 and the like of the first-first embodiment, when there are two or more blocks 76 of the MUX 76 and the ADC 77 that periodically switch the power supply state, the control unit 54 The timing of switching of the power supply state of at least two blocks BL in the block BL may be shifted.

As shown in FIG. 21 and the like of the first to fifth embodiments, when there are a plurality of blocks BL including the MUX 76 to which a part of CA is not connected, at least one of them is always kept in the second state. It is also good.

For example, in the case where the above first to twelfth embodiments of FIGS. 35 to 37 are applied to the configuration of the above third to tenth embodiment shown in FIG. 44, the detection CA 132 connected to the detection channel 95 shown in FIG. In addition to the above, the CA 60 connected to the reference channel 120 shown in FIG. 37 is a part of CA that selectively outputs the analog voltage signal V (C) to the ADC 77. That is, in the above 3-1 and 3-2 embodiments, only the detection CA 132 is illustrated as a part of CA for selectively outputting the analog voltage signal V (C) to the ADC 77. The present invention is not limited to this, but also includes the CA 60 connected to the reference channel 120.

Further, the voltage signal V (C) of an analog signal is selectively output to the ADC 77 by applying the above-described 2-1 to 2-3 embodiments of the second invention shown in FIGS. 39 to 43. The power supplied to at least one of the unselected CAs other than some of the CAs during the AED operation may be set to a power saving state lower than the normal power during the image reading operation.

Here, the non-selected CA is the non-detection CA 131 when the above first to twelfth embodiments of FIGS. 35 to 37 are not applied, and the reference channel when the above first to twelfth embodiments are applied. It is CA131 for non-detection except CA60 connected to 120. FIG.

When the above second to third embodiments are applied, not only the non-detection CA 131 but also the detection CA 132 (including the CA 60 connected to the reference channel 120 when the above first to twelfth embodiments are applied) At least one is driven in a low power state where power below normal power PN_C and greater than 0 is supplied. Therefore, it is possible to further reduce the power consumption of the signal processing circuit 51 during the AED operation.

4. Fourth Invention The fourth invention shown in FIGS. 50 to 58 described below is the case where the AED operation is performed while switching the power supply states of the plurality of ADCs 77 of the first invention and, consequently, the plurality of blocks BL1 to BL16. It is for solving the problem which arises. The fourth invention is required for the control unit 54 to stably operate the ADC 77 and the like that constitute the block BL rather than the timing for starting the charge readout for each of the plurality of blocks BL1 to BL16 in the AED operation. The content is to switch from the second state to the first state before a predetermined time.

Also in the fourth invention, as in the second and third inventions, the basic configurations of the X-ray imaging system 10, the electronic cassette 16 and the like are the same as those of the first invention described above. Also, the patterns exemplified in the above 1-1 to 1-7 embodiments can be applied to the switching pattern of the power supply state of the ADC 77. Furthermore, the other embodiments of the first invention (the above 1-8 to 1-13 embodiments), the above the 2-1 to 2-3 embodiments of the second invention, and the above-mentioned third of the third invention. A combination with the -1 and 3-2 embodiments is also possible. In the following, the same parts as those of the first to third inventions are given the same reference numerals and their explanations are omitted, and the differences will be mainly explained.

[Fourth embodiment]
A fourth embodiment is shown in FIGS. 50 and 51. In the present fourth embodiment, for example, the detection pixel 90X1 shown in FIG. 29 of the first embodiment or the detection pixel shown in FIG. Although the description is made on the assumption that the configuration includes 90X2, the configuration is not limited to this.

FIG. 50 shows the power supply state of a certain block BL. The hatched portion is a period during which the charge that is the source of the dose signal DDS (C) is read out. More specifically, charge is read out to CA 60 through signal line 42, CA 60 is sequentially selected by MUX 76, analog voltage signal V (C) based on charge is output to ADC 77, and analog voltage signal V (C) is output by ADC 77. Are converted into the dose signal DDS (C) and output.

Here, immediately after switching from the non-operating state, which is the second state, to the operating state, which is the first state, the block BL becomes unstable in operation due to the influence of temperature drift and the like. The dose signal DDS (C) outputted while the operation is unstable becomes extremely unreliable. Therefore, there is a possibility that the reliability of the determination as to whether or not the X-ray irradiation has been started can not be maintained.

FIG. 50A shows an example in which charge reading is started immediately after switching the block BL from the non-operating state to the operating state. As described above, when there is no time between the switching from the non-operating state to the operating state of the block BL and the timing for starting the charge readout, the operation is performed while the operation of the block BL is unstable. The dose signal DDS (C) increases the risk of erroneous determination of the start of X-ray irradiation.

Therefore, as shown in FIG. 50B, switching from the non-operating state to the operating state of the block BL is performed before the time TW at which the charge readout is started. The time TW is a time required to operate the block BL stably.

FIG. 51 is a flow chart showing the operation procedure of the electronic cassette of the present fourth embodiment. The points of difference with the flowchart shown in FIG. 17 of the above-described first embodiment are step ST 1204 and step ST 1804 surrounded by an alternate long and short dash line. Only the differences will be described below.

In step ST1204, in the AED operation, the control unit 54 switches the power supply state of the block BL. Then, the switching from the non-operating state to the operating state of the block BL is performed before the time TW for starting the charge readout (irradiation start detection step). In addition, in step ST1804, in the image reading operation, all the blocks BL are put into operation (image reading step).

In this way, as shown in FIG. 50A, the dose signal DDS (C) is not output while the operation of the block BL is unstable, and the risk of erroneous determination of the start of X-ray irradiation can be reduced. it can.

There are three variations shown in FIG. 52 to FIG. 54 in the period in which the charge indicated by hatching is read. 52 to 54 exemplify the block BL1 in charge of the area AR1 in the first to 144th columns, as in FIGS. 9 and 44.

First, FIG. 52 shows the case where all the signal lines 42 of the area AR1 that the block BL1 is in charge are the detection channels 95, as shown by the alphabet DT (see FIG. 44). In this case, during the charge readout period, the dose signals DDS (1) to DDS (144) based on the analog voltage signals V (1) to V (144) from the detection CA 132 of all the detection channels 95 are output. Period of time

FIG. 53 shows an analog voltage signal V (C) from the detection CA 132 of the detection channel 95 when the odd-numbered column is the detection channel 95 and the MUX is the same as the embodiment 3-1 shown in FIG. In the case of a general MUX 76 having only a function of sequentially selecting one column at a time, instead of the MUX 135 having a function of selecting. In this case, while the charge is being read out, analog voltage signals V (1), V (3), V (5),..., V (143) from the detection CA 132 of the detection channel 95 in the odd-numbered column Period during which the dose signals DDS (1), DDS (3), DDS (5),. That is, the period in which the charge is read out in this case is intermittent.

FIG. 54 is the same as FIG. 52 in that the odd-numbered column is the detection channel 95, but the MUX is not the MUX 76 but the MUX 135. In this case, while the charge is being read out, analog voltage signals V (1), V (3), V (5),..., V (143) from the detection CA 132 of the detection channel 95 in the odd-numbered column The dose signals DDS (1), DDS (3), DDS (5),... Since the charge readout period is not intermittent as shown in FIG. 53, the simple appearance is the same as in FIG. However, while in FIG. 52 the analog voltage signal V (C) is sequentially selected one by one in the MUX 76, in FIG. 54, the analog voltage signal V (C) is selected every other row in the MUX 135. The specific content is different.

Embodiment 4-2
FIGS. 55 to 57 show a fourth embodiment. Although the timing at which the block BL is switched from the non-operation state to the operation state with respect to the timing to start the charge readout is defined in the above-described fourth embodiment, the block BL is operated in the fourth to second embodiment. Define the timing to switch from to non-operational state.

When charge is being read out in another block BL when one block BL is switched from the operating state to the non-operating state, switching noise and the like generated by switching the block BL from the operating state to the non-operating state , There is a risk of getting on the charge of the other block BL. Therefore, in the present fourth embodiment, switching from an operating state to a non-operating state of a certain block BL is performed at timings that do not overlap with timings during which charge is being read in another block BL.

55 to 57 are similar to FIG. 14 of the first-first embodiment, FIG. 18 of the first-second embodiment, and the like, and supply of power to the blocks BL1 to BL16 (not shown after the block BL5). The case where the state is periodically switched and the timing of switching the power supply state of each block BL1 to BL16 is shifted is illustrated. 55 and 56 illustrate the case where the charge readout period is a variation of FIG. 52 or 54, and FIG. 57 illustrates the charge readout period a variation of FIG. 53, respectively.

FIG. 55 is a timing before starting to read out the charge from the detection CA 132 of each of the blocks BL1 to BL16, as indicated by the broken arrows, in which the blocks BL1 to BL16 are switched from the operating state to the non-operating state. Specifically, this is an example performed during startup of the time TW. More specifically, in FIG. 55, the control unit 54 switches the operating state of the block BL1 to the non-operating state during start-up of the block BL2, and switches the operating state of the block BL2 to the non-operating state. It is performed during the start of block BL3. Further, switching from the operating state of the block BL3 to the non-operating state is performed during the startup of the block BL4.

FIG. 56 shows an example in which switching from the operating state to the non-operating state of each of the blocks BL1 to BL16 is performed at the timing after the readout of the charge from the detection CA 132 of each of the blocks BL1 to BL16 is completed. More specifically, in FIG. 56, the control unit 54 switches the operating state of the block BL1 to the non-operating state after reading of the charge of the block BL2 is completed, and switches the operating state of the block BL2 to the non-operating state. , And after completion of reading out the charge of the block BL3. Further, switching from the operating state of the block BL3 to the non-operating state is performed after the end of the charge reading of the block BL4.

FIG. 57 shows an example in which switching from the operating state to the non-operating state of each of the blocks BL1 to BL16 is performed in the interval between the intermittent charge reading of each of the blocks BL1 to BL16. More specifically, in FIG. 57, the control unit 54 switches the operating state of the block BL1 to the non-operating state in the interval between the intermittent charge reading of the block BL2 and starts the operating state of the block BL2. The switching to the non-operating state is performed between the intermittent charge reading periods of the block BL3. Then, switching from the operating state to the non-operating state of the block BL3 is performed in the interval of the intermittent charge reading of the block BL4.

As described above, switching of the block BL from the operating state to the non-operating state is performed if switching from the operating state to the non-operating state of the block BL is performed at timings that do not overlap with timings during reading of electric charges in other blocks BL. There is no possibility that the switching noise and the like generated in the above may be carried on the charge of the other block BL.

From the viewpoint of power saving, among the examples of FIGS. 55 to 57, switching of the blocks BL1 to BL16 from the operating state to the non-operating state is performed prior to the start of charge reading of the blocks BL1 to BL16. The example is most preferred.

[4-3 Embodiment]
A fourth embodiment is shown in FIG. As shown in FIG. 35 of the first to twelfth embodiments, when the power supply state of each block BL is switched in the AED operation, deviation of the temperature distribution occurs in the block BL. If the deviation of the temperature distribution is not resolved before the image reading operation for obtaining the X-ray image to be diagnosed, temperature drift occurs in the image signal DIS (C) and the image quality of the X-ray image is degraded. Therefore, in the fourth embodiment, after the control unit 54 detects the start of the X-ray irradiation in the AED operation, all the blocks BL are put into operation until the image reading operation is started.

In FIG. 58, all the blocks BL1 to BL16 are in operation at the timing when the start of X-ray irradiation is detected in the AED operation. More specifically, in FIG. 58, the control unit 54 operates the blocks BL (blocks BL3, BL4, BL7, BL8, BL11, BL12, BL15, BL16) that were inoperative when detecting the start of X-ray irradiation. Switch to On the other hand, the control unit 54 continues the operating state of the blocks BL (the blocks BL1 and BL2 other than the above) which are in the operating state at the detection of the X-ray irradiation start.

Further, in FIG. 58, all the blocks BL1 to BL16 are immediately put into operation at the timing when the start of X-ray irradiation is detected in the AED operation. Therefore, after detecting the start of X-ray irradiation, all blocks BL1 are detected. It can be said that all the blocks BL1 to BL16 are in the operating state during the reading cycle TX of the dose signal DDS (C) in which the switching of .about.BL16 ends one cycle.

As described above, after detecting the start of X-ray irradiation in the AED operation, all the blocks BL are put into operation before the image reading operation is started. Therefore, in the image reading operation, each block BL in the AED operation. It is highly possible that the deviation of the temperature distribution in the block BL, which is caused by switching the power supply state of the power supply, is eliminated. Therefore, the temperature distribution does not occur in the image signal DIS (C) due to the deviation of the temperature distribution in the block BL, and an X-ray image of good image quality can be obtained.

In addition, after detecting the start of X-ray irradiation, all blocks BL1 to BL16 are put into operation during the read cycle TX of the dose signal DDS (C) in which switching of all the blocks BL1 to BL16 ends one cycle. Therefore, it is possible to secure a sufficient time for eliminating the deviation of the temperature distribution in the block BL by the start of the image reading operation.

The timing at which all the blocks BL1 to BL16 are brought into the operating state may be any timing in the period from the start of the X-ray irradiation detection in the AED operation to the start of the image reading operation. However, as shown in FIG. 58, all the blocks BL1 to BL16 are put into operation at the timing when the start of X-ray irradiation is detected by the AED operation as shown in FIG. Is preferred. The definitions of the operating state and the non-operating state, and hence the first state and the second state, are as described at the end of the second invention.

In addition, the time TW required for stably operating the block BL may be almost the same as the time taken to prepare for operation of the CA 60, the CDS 61, the MUX 76, and the ADC 77 constituting the block BL, or longer than that. In some cases. The fourth invention also includes the case where the time TW required for stably operating the block BL is substantially the same as the time taken to prepare for the operation of the CA 60, the CDS 61, the MUX 76, and the ADC 77 constituting the block BL. That is, the case of starting the charge readout immediately after the preparation of the operation of the CA 60, the CDS 61, the MUX 76, and the ADC 77 constituting the block BL is also included in the fourth invention.

The power supplied to each part of the block BL during the time TW may be changed according to the temperature of the block BL. For example, when the temperature of the block BL before the time TW is much lower than the target temperature, the control unit 54 applies a relatively large amount of power to each part of the block BL to reach the target temperature in a short time. On the other hand, if the temperature of the block BL before the time TW is lower than the target temperature but relatively close to the target temperature, the target temperature may be exceeded if relatively large power is applied to each part of the block BL. Because of this, the control unit 54 operates the components of the block BL with relatively low power.

As described above, each embodiment of the fourth invention may be implemented in combination with each embodiment of the first invention, the second invention, and the third invention. For example, as in the case of the second and third inventions, the first invention is applied, and the ADC 54 is controlled by the control unit 54 as shown in FIG. 14 and the like of the first-first embodiment. The power supply state of the MUX 76 constituting the block BL may be periodically switched to the first state and the second state.

Similar to the second and third inventions, combinations of the ADC77 of the fourth invention and the ADC77 of the first invention, and eventually the switching pattern of the supply power of the block BL can be, for example, the following combinations. First, as shown in FIG. 14 and the like of the first-first embodiment, when there are two or more blocks 76 of the MUX 76 and the ADC 77 that periodically switch the power supply state, the control unit 54 The timing of switching of the power supply state of at least two blocks BL in the block BL may be shifted.

Furthermore, the above-described Embodiments 3-1 and 3-2 in which the number of pulses per unit time of the clock signal of the ADC 77 shown in FIG. 44 to FIG.

5. Fifth Invention The fifth invention shown in FIGS. 59 and 60 described below is that the control unit 54 reduces the power supplied to the CA 60 in the AED operation as compared to that in the image read operation. In the second invention, the power supplied to at least one of the non-detection CAs 131 during the AED operation is set to a power saving state lower than the normal power during the image reading operation. The invention is different from the second invention in that the power supplied to the CA 60 is reduced during AED operation than during image read operation, without distinction between the detection CA 132 and the non-detection CA 131.

Also in the fifth invention, as in the second to fourth inventions, the basic configurations of the X-ray imaging system 10, the electronic cassette 16 and the like are the same as those of the first invention described above. In the following, the same parts as those of the first to fourth inventions are given the same reference numerals and their explanations are omitted, and the differences will be mainly explained.

As shown in FIG. 59, the control unit 54 sets the supplied power P_C to all the CAs 60 in the image reading operation as the normal power PN_C, and the supplied power P_C to all the CAs 60 in the AED operation is PL_C lower than PN_C. I assume.

FIG. 60 is a flow chart showing the operation procedure of the electronic cassette of the fifth invention. The difference between the flowchart shown in FIG. 17 of the first-first embodiment and the flowchart shown in FIG. 17 is step ST1205 and step ST1805 surrounded by an alternate long and short dash line. Only the differences will be described below.

In step ST1205, in the AED operation, all the CAs 60 are driven with low power by the supplied power PL_C. On the other hand, in the image reading operation in step ST1805, all the CAs 60 are driven by the normal power PN_C.

As described above, since the power supplied to the CA 60 is reduced during the AED operation compared to the image reading operation, the power consumption of the signal processing circuit 51 during the AED operation can be reduced. Therefore, as in the first to third inventions, the battery 65 lasts longer than in the prior art, and the number of times the battery 65 is charged is also reduced, so that the imaging efficiency can be improved.

From the above description, it is possible to grasp an operation method of the radiation image detection apparatus according to the following supplementary item 1 and the radiation image detection apparatus according to the supplementary item 2.

[Appendix 1]
A sensor panel in which pixels which are irradiated from the radiation generating apparatus and sensitive to the radiation transmitted through the subject and store electric charges in a two-dimensional manner, and which are provided with a plurality of signal lines for reading out the electric charges;
A signal processing circuit that performs signal processing by reading an analog voltage signal corresponding to the charge from the pixel through the signal line;
A plurality of charge amplifiers included in the signal processing circuit, provided for each of the signal lines and connected to one end of the signal lines, for converting the charges from the pixels into the analog voltage signals Charge amplifier,
A multiplexer included in the signal processing circuit, the multiplexer having a plurality of input terminals, the plurality of charge amplifiers being respectively connected to the plurality of input terminals, and the analog voltage signals from the plurality of charge amplifiers being sequentially A multiplexer to select and output,
An AD converter included in the signal processing circuit, which is connected to a subsequent stage of the multiplexer and executes AD conversion processing for converting the analog voltage signal output from the multiplexer into a digital signal according to a voltage value AD converter,
And a control unit that controls the signal processing circuit to execute an irradiation start detection operation and an image readout operation.
The irradiation start detection operation is an operation of reading out the charge from the pixel through the signal line before the start of irradiation of the radiation and detecting the start of irradiation of the radiation based on the digital signal corresponding to the read charge. And
The image readout operation corresponds to the readout charge by reading out the charge from the pixel through the signal line after a pixel charge accumulation period for accumulating the charge in the pixel has elapsed after the start of the irradiation of the radiation. An operation of outputting a radiation image to be provided for diagnosis represented by the digital signal
The said control part is a radiographic image detection apparatus which reduces the electric power supply to all the said charge amplifiers in the said irradiation start detection operation rather than the time of the said image read-out operation.

[Appendix 2]
A sensor panel in which pixels which are irradiated from the radiation generating apparatus and sensitive to the radiation transmitted through the subject and store charges are arranged in a two-dimensional manner, and a plurality of signal lines for reading out the charges are arranged; A signal processing circuit that performs signal processing by reading an analog voltage signal according to the charge from a pixel, and a plurality of charge amplifiers included in the signal processing circuit, provided for each of the signal lines, and the signal line A plurality of charge amplifiers connected to one end of the plurality of charge amplifiers for converting the charges from the pixels into analog voltage signals, and a multiplexer included in the signal processing circuit, the plurality of charge terminals having a plurality of input terminals; An amplifier is connected to each of the plurality of input terminals to sequentially select and output the analog voltage signals from the plurality of charge amplifiers. And an AD converter included in the signal processing circuit, which is connected to a subsequent stage of the multiplexer and converts the analog voltage signal output from the multiplexer into a digital signal according to a voltage value In an operation method of a radiation image detection apparatus comprising: an AD converter for performing
Before the start of the irradiation of radiation, the charge is read out from the pixel through the signal line, and the irradiation start detection operation of detecting the start of irradiation of the radiation based on the digital signal corresponding to the read charge is performed Start detection step,
After the start of the radiation irradiation, a pixel charge accumulation period for accumulating the charge in the pixel elapses, and then the charge is read from the pixel through the signal line, and the digital signal corresponding to the read charge is represented And an image reading step of executing an image reading operation of outputting a radiation image to be provided for diagnosis.
A method of operating a radiation image detection apparatus, wherein power supplied to all of the charge amplifiers in the irradiation start detection step is reduced as compared to that in the image reading operation.

In addition, step ST1205 and step ST1805 of FIG. 60 correspond to the irradiation start detection step and the image readout step described in the additional item 2, respectively.

6. Sixth Invention In the sixth invention shown in FIGS. 61 and 62 described below, the control unit 54 reduces the number of pulses per unit time of the clock signal of the ADC 77 at the time of the AED operation as compared to that at the time of the image reading operation. It is the contents of that. The third invention selectively outputs analog voltage signals V (C) from some of the CAs including the detection CA 132 to the ADC 77, and selectively outputs the analog voltages to the ADC 77. The content is that the number of pulses per unit time of the clock signal of the ADC 77 at the time of the AED operation is reduced as compared with that at the time of the image reading operation after performing only the AD conversion processing on the signal V (C). In contrast, the sixth invention carries out AD conversion processing on the analog voltage signals V (C) from all the CAs 60 in the ADC 77 as in the image read-out operation regardless of the detection CA 132 and the non-detection CA 131. The third embodiment is different from the third invention in that the number of pulses per unit time of the clock signal of the ADC 77 at the time of AED operation is reduced as compared with that at the time of image reading operation.

Also in the sixth invention, as in the second to fifth inventions, the basic configurations of the X-ray imaging system 10, the electronic cassette 16 and the like are the same as those of the first invention described above. Hereinafter, the same parts as those of the first to fifth inventions will be assigned the same reference numerals and explanations thereof will be omitted, and differences will be mainly described.

As shown in FIG. 61, the control unit 54 controls the pulse number NPU_A per unit time of the clock signal of all the ADCs 77, NPUN_A which is a normal pulse number at the time of image reading operation, and 1⁄2 of NPUN_A at AED operation. Let's call it NPUL_A.

FIG. 62 is a flow chart showing the operation procedure of the electronic cassette of the sixth invention. The point of difference between the flowchart shown in FIG. 17 of the first-first embodiment and the flowchart shown in FIG. 17 is step ST1206 and step ST1806 surrounded by a dashed dotted line. Only the differences will be described below.

In step ST1206, in the AED operation, a clock signal NPUL_A which is 1/2 the pulse number NPUN_A which is a normal pulse number is supplied to all the ADCs 77. On the other hand, in the image readout operation in step ST1806, a normal clock signal of pulse number NPUN_A is supplied to all the ADCs 77.

As described above, since the number of pulses per unit time of the clock signal of the ADC 77 at the time of AED operation is reduced as compared with that at the time of image reading operation, power consumption of the signal processing circuit 51 at the time of AED operation can be reduced. Therefore, as in the first to third and fifth aspects of the invention, the battery 65 lasts longer than in the prior art, and the number of times the battery 65 is charged is also reduced, so that the imaging efficiency can be improved.

From the above description, it is possible to comprehend the radiation image detection apparatus according to the following supplementary item 3 and the operation method of the radiation image detection apparatus according to the supplementary item 4.

[Appendix 3]
A sensor panel in which pixels which are irradiated from the radiation generating apparatus and sensitive to the radiation transmitted through the subject and store electric charges in a two-dimensional manner, and which are provided with a plurality of signal lines for reading out the electric charges;
A signal processing circuit that performs signal processing by reading an analog voltage signal corresponding to the charge from the pixel through the signal line;
An AD converter that is included in the signal processing circuit and executes an AD conversion process for converting the analog voltage signal into a digital signal according to a voltage value, the AD conversion process being performed for each of the signal lines With multiple AD converters to share
And a control unit that controls the signal processing circuit to execute an irradiation start detection operation and an image readout operation.
The irradiation start detection operation is an operation of reading out the charge from the pixel through the signal line before the start of irradiation of the radiation and detecting the start of irradiation of the radiation based on the digital signal corresponding to the read charge. And
The image readout operation corresponds to the readout charge by reading out the charge from the pixel through the signal line after a pixel charge accumulation period for accumulating the charge in the pixel has elapsed after the start of the irradiation of the radiation. An operation of outputting a radiation image to be provided for diagnosis represented by the digital signal
The control unit reduces the number of pulses per unit time of the clock signal that defines the operation timing of the AD converter for all the AD converters in the irradiation start detection operation as compared to the image read operation. Radiation image detector.

[Appendix 4]
A sensor panel in which pixels which are irradiated from the radiation generating apparatus and sensitive to the radiation transmitted through the subject and store charges are arranged in a two-dimensional manner, and a plurality of signal lines for reading out the charges are arranged; A signal processing circuit that performs signal processing by reading an analog voltage signal according to the charge from a pixel, and an AD conversion process included in the signal processing circuit and converting the analog voltage signal into a digital signal according to a voltage value Operation of a radiation image detection apparatus including: a plurality of AD converters that share the AD conversion process performed for each signal line; and a control unit that controls the signal processing circuit. In the method
Before the start of the irradiation of radiation, the charge is read out from the pixel through the signal line, and the irradiation start detection operation of detecting the start of irradiation of the radiation based on the digital signal corresponding to the read charge is performed Start detection step,
After the start of the radiation irradiation, a pixel charge accumulation period for accumulating the charge in the pixel elapses, and then the charge is read from the pixel through the signal line, and the digital signal corresponding to the read charge is represented And an image reading step of executing an image reading operation of outputting a radiation image to be provided for diagnosis.
In the radiation start detection step, for all the AD converters, the number of pulses per unit time of a clock signal that defines the operation timing of the AD converters is reduced compared to that at the time of the image reading operation. How it works

In addition, step ST1206 and step ST1806 of FIG. 62 correspond to the irradiation start detection step and the image readout step described in the supplementary item 4, respectively.

7. Seventh Invention The seventh invention shown in FIGS. 63 and 64 described below is a modification of the circuit configuration. Also in the seventh invention, as in the second to sixth inventions, the basic configurations of the X-ray imaging system 10, the electronic cassette 16 and the like are the same as those of the first invention described above. In the following, the same parts as those of the first to sixth inventions will be assigned the same reference numerals and explanations thereof will be omitted, and differences will be mainly described.

63 and 64 show a circuit configuration of one block BL and its periphery in the seventh invention. The block BL is a mixture of the detection channel 95 and the non-detection channel 130 as in the above-mentioned second embodiment shown in FIG. The detection channel 95 is divided into a first path 140 and a second path 141 at a stage subsequent to the CDS 61 as in the third embodiment shown in FIG. 49, and the switch 142 is connected. The switch 142 switches the path connected to the detection channel 95 between the first path 140 and the second path 141 in response to the drive control signal S_MUX input from the control unit 54.

The detection channel 95 and the non-detection channel 130 are divided into a first path 200 and a second path 201 before the detection CA 132 and the non-detection CA 131. The first path 200 is connected to the detection CA 132 and the non-detection CA 131. The second path 201 is connected to the CDS 61 without passing through the detection CA 132 and the non-detection CA 131. The first path 200 is a path for inputting a charge to the detection CA 132 and the non-detection CA 131. The second path 201 is a path for outputting charge to the MUX 76 without passing through the detection CA 132 and the non-detection CA 131.

A switch 202 is connected to the detection channel 95 or the non-detection channel 130, the first path 200, and the second path 201. The switch 202 switches the path connected to the detection channel 95 or the non-detection channel 130 between the first path 200 and the second path 201 in accordance with the drive control signal S_CA input from the control unit 54.

Similarly, in the front stage of the CDS 61, the detection channel 95 and the non-detection channel 130 are divided into a first path 203 and a second path 204, and the switch 205 is connected. The switch 205 switches the path connected to the detection channel 95 or the non-detection channel 130 between the first path 203 and the second path 204 according to the drive control signal S_CDS input from the control unit 54.

A bias power supply 207 is connected to the detection channel 95 and the non-detection channel 130 via the switch 206. The switch 206 is switched on / off in response to the drive control signal S_BIAS input from the control unit 54.

The control unit 54 individually outputs the drive control signals S_MUX, S_CA, and S_CDS to the

switches

142, 202, and 205 of the channels 95 and 130 (the signal lines 42). Therefore, the control unit 54 sets the

switches

202 and 205 of the detection channel 95 to the

first paths

200 and 203, and sets the

switches

202 and 205 of the non-detection channel 130 to the

second paths

201 and 204. Individual drive control of each

switch

142, 202, 205 is possible. Similarly for the switch 206, the control unit 54 can individually output the drive control signal S_BIAS, the detection channel 95 can be turned off, the non-detection channel 130 can be turned on, and so on.

FIG. 63 shows the time of image read operation. That is, the

first paths

140, 200, and 203 are selected by the

switches

142, 202, and 205, respectively. Also, the switches 206 are all in the off state.

On the other hand, at the time of the AED operation, for example, the state shown in FIG. That is, in the detection channel 95, the switch 142 selects the second path 141, and the

switches

202 and 205 select the

first paths

200 and 203, respectively. Also, the switch 206 is still in the off state. This state is the same as the state of FIG. 49A of the third-2 embodiment. Therefore, as described in the third embodiment, the analog voltage signal V (C) from the detection CA 132 is directly output to the ADC 77 without passing through the MUX 76.

On the other hand, in the non-detection channel 130, the

second paths

201 and 204 are selected by the

switches

202 and 205, respectively. Also, the switch 206 is in the on state. In this case, the charge of the non-detection channel 130 is directly output to the MUX 76 without passing through the non-detection CA 131 and the CDS 61. Further, a bias voltage is applied to the non-detection channel 130 from the bias power supply 207 through the switch 206.

In this case, the non-detection CA 131 is in a power-off state where the supplied power PL_C is 0, as in the second to second embodiments shown in FIG. Similarly, the CDS 61 of the non-detection channel 130 is in the power off state.

When the non-detection CA 131 is in the power-off state, the virtual short state between the two input terminals of the non-detection CA 131 can not be maintained as described in the second embodiment, and the non-detection CA 131 can not be maintained. The potential of the input stage becomes unstable, and accordingly, the charges of the non-detection channel 130 also become unstable, which adversely affects the subsequent image reading operation. Therefore, in the seventh invention, the switch 206 is turned on, and a bias voltage is applied to the non-detection channel 130 from the bias power supply 207. As a result, the above-mentioned problem that the charge of the non-detection channel 130 becomes unstable and adversely affects the image reading operation later can be solved.

The non-detection CA 131 may not be in the power off state, but may be set to the low power state by supplying the supply power PL_C to such an extent that the potential of the input stage is not unstable as in the above-described second embodiment.

As in the second to third embodiments shown in FIG. 43, not only the non-detection CA 131 but also the detection CA 132 are driven in a low power state in which power lower than the normal power PN_C and greater than 0 is supplied. You may However, also in this case, as shown in FIG. 64, in the AED operation, in the detection channel 95, the second path 141 is selected by the switch 142, and the

first paths

200 and 203 are selected by the

switches

202 and 205, respectively. 206 is turned off.

Further, when the detection CA 132 is driven in a low power state, the detection performance of the detection CA 132 is lowered, and accordingly, the S / N ratio of the dose signal DDS (C) may be lowered. Therefore, the number of gate lines 41 for simultaneously applying gate pulses G (R) from the gate drive unit 50 is increased to increase the amount of charges added in the detection channel 95, and the S / N of the dose signal DDS (C) It is preferred to improve the ratio.

The control unit 54 does not individually output the drive control signals S_MUX, S_CA, S_CDS, S_BIAS to the

switches

142, 202, 205, 206 of the channels 95, 130 (the signal lines 42), respectively. The drive control signals S_MUX, S_CA, S_CDS, and S_BIAS may be output uniformly in units of blocks BL. For example, as in the first to fifth embodiments, the block BL in which the ADC 77 is always inoperative is such that the uniform switches 142, 202, and 205 are on the

second paths

141, 201, and 204 side, and the uniform switch 206 is in the on state. .

The switch 206 and the bias power supply 207 may be incorporated in the block BL and hence in the signal processing circuit 51.

With the detection CA 132 in the power-off state and the switch 206 in the on state, a bias voltage is applied from the bias power supply 207 to the detection channel 95, and the

switches

202 and 205 of the detection channel 95 are connected to the

second paths

201 and 204 side. Do. Then, the load fluctuation of the bias power supply 207 caused by the current flowing to the pixel 40 at the time of X-ray irradiation is converted by the ADC 77 into a digital signal DS (C). This may be used as the dose signal DDS (C), and when the dose signal DS (C) fluctuates beyond a predetermined range, it may be determined that the X-ray irradiation has been started.

Similarly, with the non-detection CA 131 in the power-off state and the switch 206 in the on state, a bias voltage is applied from the bias power supply 207 to the non-detection channel 130, and the

switches

202 and 205 of the non-detection channel 130 are The

paths

201 and 204 are set. Then, the load fluctuation of the bias power supply 207 caused by the current flowing to the pixel 40 at the time of X-ray irradiation is converted by the ADC 77 into a digital signal DS (C). This may be used as the dose signal DDS (C), and when the dose signal DS (C) fluctuates beyond a predetermined range, it may be determined that the X-ray irradiation has been started.

Alternatively, a dose signal DDS (C) representing the load fluctuation of the bias power supply 207 output from the detection channel 95 and a dose signal DDS representing the load fluctuation of the bias power supply 207 output from the non-detection channel 130 (C) The start of X-ray irradiation may be determined based on both of the above. Specifically, the difference or ratio of each dose signal DDS (C) is calculated, and the start of X-ray irradiation is determined based on the calculated difference or ratio. In this case, noise components such as shock, vibration noise, and electromagnetic noise applied to the electronic cassette 16 are canceled, so that it is possible to reduce the possibility of erroneous determination of the start of X-ray irradiation due to the noise components.

The potential of the input stage of the detecting CA 132 or the non-detecting CA 131 is not indefinite as in the above-described second embodiment, instead of setting the detecting CA 132 or the non-detecting CA 131 to the power-off state Power supply PL_C may be given to set the low power state.

The power supply for acquiring the dose signal DDS (C) representing the load fluctuation is not limited to the bias power supply 207. Any power supply such as the power supply of the ADC 77, the CA 60, or the CDS 61 may be used as long as the power is on during the operation of the AED.

However, when it is determined by the dose signal DDS (C) representing load fluctuation of the power supply whether or not the X-ray irradiation has been started, the load fluctuation of the power supply is small. There is a possibility that the N ratio is lowered and the X-ray irradiation start detection performance is lowered.

Therefore, the number of gate lines 41 to which gate pulses G (R) are simultaneously given from the gate driver 50 is increased to increase the amount of charges added in the detection channel 95 or the non-detection channel 130, It is preferable to improve the S / N ratio of C). Alternatively, the S / N ratio of the dose signal DDS (C) may be improved by adding or averaging the dose signals DDS (C) between adjacent channels. Furthermore, there is a method of increasing the number of charges added in each channel by increasing the number of gate lines 41 that simultaneously apply gate pulses G (R) from the gate driver 50, and the dose signal DDS between adjacent channels The S / N ratio of the dose signal DDS (C) may be further improved by using a method of adding or averaging C).

The seventh aspect of the present invention may be implemented in combination with the respective embodiments of the first aspect, the second aspect, the third aspect, and the fourth aspect of the invention. For example, as in the case of the second to fourth inventions, as described in FIG. 14 and the like of the first-first embodiment applying the first invention, the control unit 54 controls the ADC 77, and The power supply state of the MUX 76 constituting the block BL may be periodically switched to the first state and the second state.

Similar to the second to fourth inventions, combinations of the ADC77 of the seventh invention and the ADC77 of the first invention and the switching pattern of the supply power of the block BL can be, for example, the following combinations. First, as shown in FIG. 14 and the like of the first-first embodiment, when there are two or more blocks 76 of the MUX 76 and the ADC 77 that periodically switch the power supply state, the control unit 54 The timing of switching of the power supply state of at least two blocks BL in the block BL may be shifted.

Furthermore, in the AED operation shown in FIG. 50 to FIG. 58, it is necessary to stably operate the ADC 77 etc. constituting the block BL rather than the timing for starting the charge readout for each of the plurality of blocks BL1 to BL16. The fourth to fourth embodiments may be applied to switch from the second state to the first state before a predetermined time.

In each of the embodiments of the first to seventh inventions, the electronic cassette 16 is illustrated as a radiation image detection apparatus, but the present invention is not limited to this. The present invention is also applicable to a stationary radiation image detection apparatus fixed to the standing position imaging stand 18 and the deceiving position imaging stand 19.

In each embodiment of the first to seventh inventions, for example, the hardware structure of a processing unit that executes various processes such as the control unit 54, the leak charge correction unit 121, and the temperature drift correction unit 122 , And various processors as shown below.

The various processors include a CPU, a programmable logic device (PLD), a dedicated electric circuit, and the like. The CPU is a general-purpose processor that executes software (program) and functions as various processing units, as is well known. The PLD is a processor that can change the circuit configuration after manufacture, such as an FPGA (Field Programmable Gate Array). The dedicated electric circuit is a processor having a circuit configuration specially designed to execute a specific process such as an application specific integrated circuit (ASIC).

One processing unit may be configured of one of these various processors, or configured of a combination of two or more processors of the same type or different types (for example, a plurality of FPGAs or a combination of a CPU and an FPGA) It may be done. In addition, a plurality of processing units may be configured by one processor. As an example of configuring a plurality of processing units by one processor, first, there is a form in which one processor is configured by a combination of one or more CPUs and software, and this processor functions as a plurality of processing units. . Second, as typified by a system on chip (SoC) or the like, there is a mode using a processor that realizes functions of the entire system including a plurality of processing units by one IC chip. Thus, the various processing units are configured using one or more of the above-described various processors as a hardware structure.

Furthermore, the hardware-like structure of these various processors is more specifically an electric circuit (circuitry) combining circuit elements such as semiconductor elements.

The present invention can be applied not only to X-rays but also to other radiations such as γ-rays.

Note that the conjunctions “or”, “or”, “or” described in the present specification may have a restrictive interpretation that, depending on the context, any one of a plurality of options connected by these conjunctions. Is not an intentional expression but an expression that includes a combination of multiple options. For example, the sentence "Perform Option A or Option B" has three ways depending on the context: "Perform Option A", "Perform Option B", "Perform Option A and Option B". It should be interpreted that there is

The present invention is not limited to the embodiments of the first to seventh inventions, and it goes without saying that various configurations can be adopted without departing from the scope of the present invention. Furthermore, the present invention extends to a storage medium for storing a program in addition to the program.

DESCRIPTION OF SYMBOLS 10 X-ray imaging system 11 X-ray generator 12 X-ray imaging apparatus 13 X-ray source 14 Radiation source control apparatus 15 Irradiation switch 16 Electronic cassette (radiographic image detection apparatus)
DESCRIPTION OF SYMBOLS 17 console 18 standing imaging stand 19 repositioning stand 20 display 21

input device

22, 23 radio | wireless communication part 25 menu * condition table 30 sensor panel 31 circuit part 32 housing 32A front 33 transparent board 34 scintillator 35 light detection board | substrate 40

pixels

41, 107 gate line 42

signal line

43, 105

photoelectric conversion unit

44, 106 TFT
50, 108 Gate drive unit 51 Signal processing circuit 52 Memory 53 Power supply unit 54 Control unit 60 Charge amplifier (CA)
61 Correlated Double Sampling Circuit (CDS)
62 multiplexer (MUX) section 63 AD converter (ADC) section 65 battery 66 wired communication section 70 operational amplifier 71 capacitor 72 unpreset switch 73A first sample and hold circuit (first S / H)
73B 2nd sample and hold circuit (2nd S / H)
74 differential amplifier 75 (first to twelfth)

gate drive circuits

76, 76A, 76B, 135 (first to sixteenth) MUX
77 (1st to 16th) ADC
90, 90X, 90X1 to 90X3 detection pixels 95 detection channel 100 short circuit line 120 reference channel 121 leak charge correction unit 122 temperature drift correction unit 125 LVDS interface (I / F)
126 CMOS interface (I / F)
127 switch 130 channel for non-detection 131 CA for non-detection
132 Detection CA
133

switch

140, 200, 203

first path

141, 201, 204

second path

142, 202, 205, 206 switch 207 bias power supply G (R) gate pulse V (C) analog voltage signal DS (C) digital signal DIS (C) Image signal DDS (C) Dose signal RCDDS (C) Leakage charge corrected dose signal DRCDDS (C) Temperature drift corrected dose signal AR1 to AR16 Area BL1 to BL16 block CP1 to CP4 chip T Unit time P_A, PON_A, PSL_A Supply power to ADC ST100 to ST190, ST1202 to ST1206, ST1802 to ST1806, ST300 to ST330 Step LA1, LA2 area RLA1 to RLA3 Range α (C) Correction coefficient F {DRS (C-1), RS (C + 1)} Calculation formula for correction coefficient Charge at the center of the TP block SC Charge generated at the detection pixel LC Charge Charge to the P_C, PN_C, PL_C, PL_C1, PL_C2 CA Alphabet for indicating the channel for DT detection Alphabet NPU_A, NPUN_A, NPUL_A for indicating non-detection channels, pulse number per unit time of clock signal of ADCL CLN_A, clock signal of CLL_A ADC TC clock signal period Time necessary for stable operation of TW block TX dose Signal readout cycle S_MUX, S_CA, S_CDS, S_BIAS Switch drive control signal

Claims

A sensor panel in which pixels which are irradiated from the radiation generating apparatus and sensitive to the radiation transmitted through the subject and store electric charges in a two-dimensional manner, and which are provided with a plurality of signal lines for reading out the electric charges;
A signal processing circuit that performs signal processing by reading an analog voltage signal corresponding to the charge from the pixel through the signal line;
A plurality of charge amplifiers included in the signal processing circuit, provided for each of the signal lines and connected to one end of the signal lines, for converting the charges from the pixels into the analog voltage signals Charge amplifier,
A multiplexer included in the signal processing circuit, the multiplexer having a plurality of input terminals, the plurality of charge amplifiers being respectively connected to the plurality of input terminals, and the analog voltage signals from the plurality of charge amplifiers being sequentially A multiplexer to select and output,
An AD converter included in the signal processing circuit, which is connected to a subsequent stage of the multiplexer and executes AD conversion processing for converting the analog voltage signal output from the multiplexer into a digital signal according to a voltage value AD converter,
And a control unit that controls the signal processing circuit to execute an irradiation start detection operation and an image readout operation.
In the irradiation start detection operation, the electric charge is read out through the detection channel which is the signal line connected to the detection pixel preset among the pixels before the irradiation start of the radiation, and the electric charge is read out. It is an operation of detecting the start of irradiation of the radiation based on the corresponding digital signal,
The image readout operation corresponds to the readout charge by reading out the charge from the pixel through the signal line after a pixel charge accumulation period for accumulating the charge in the pixel has elapsed after the start of the irradiation of the radiation. An operation of outputting a radiation image to be provided for diagnosis represented by the digital signal
The control unit is a part of charge amplifiers including a detection charge amplifier that is the charge amplifier connected to the detection channel among the plurality of charge amplifiers connected to the multiplexer in the irradiation start detection operation Selectively output the analog voltage signal from the AD converter to the AD converter,
The control unit causes the AD converter to execute only the AD conversion process to the selectively output analog voltage signal.
Furthermore, the control unit reduces the number of pulses per unit time of a clock signal that defines the operation timing of the AD converter, as compared with the time of image reading.
Furthermore, in the irradiation start detection operation, when the power supplied to the charge amplifier at the time of the image reading operation is a normal power in the irradiation start detection operation, at least one of the partial charge amplifiers is the normal power A radiation image detection device driven in a low power state in which a power lower than 0 and greater than 0 is supplied.
The radiation image detecting apparatus according to claim 1, wherein the multiplexer has a function of selecting the analog voltage signal from the partial charge amplifier among the plurality of charge amplifiers connected.
A first path for outputting the analog voltage signal from the charge amplifier to the AD converter via the multiplexer;
A second path for outputting the analog voltage signal from the charge amplifier to the AD converter without passing through the multiplexer;
A switch selectively switching between the first path and the second path;
The radiation image detection apparatus according to claim 1, wherein the control unit controls the switch to select the second path during the irradiation start detection operation.
The control unit, in the irradiation start detection operation, supplies at least one of non-selected charge amplifiers other than the partial charge amplifier among the plurality of charge amplifiers connected to the multiplexer with the supplied power. The radiation image detection apparatus according to any one of claims 1 to 3, wherein the power saving state is lower than the normal power.
The radiation image detection apparatus according to claim 4, wherein the power saving state is a low power state in which power lower than the normal power and larger than 0 is supplied.
The radiation image detection apparatus according to claim 4, wherein the power saving state is a power off state in which the supply of the power is stopped.
The radiation image detecting apparatus according to any one of claims 4 to 6, wherein the control unit puts all of the unselected charge amplifiers in the power saving state.
A first path for inputting the charge to the charge amplifier;
A second path for outputting the charge to the multiplexer without passing through the charge amplifier;
A switch selectively switching between the first path and the second path;
The radiation image detection apparatus according to any one of claims 4 to 7, wherein the control unit controls the switch to select the second path for the unselected charge amplifiers in the power saving state. .
When the power saving state is a power off state in which the supply of the power is stopped:
The radiation image detecting apparatus according to claim 8, wherein the control unit applies a bias voltage for stabilizing the potential of the input stage to the unselected charge amplifier in the power-off state.
And a plurality of blocks each including one multiplexer to which at least one detection charge amplifier is connected and one AD converter connected to a subsequent stage of the one multiplexer,
The control unit is configured to supply power to the block in a first state for supplying a first power and a second state for supplying a second power having a lower power per unit time than the first power. Has the ability to switch between
The radiation image detection apparatus according to any one of claims 1 to 9, wherein the power supply state of at least one of the plurality of blocks is periodically switched during the irradiation start detection operation.
When there are two or more blocks in which the power supply state is periodically switched, the control unit determines the timing of switching the power supply state of at least two blocks of the two or more blocks. The radiographic image detection apparatus of Claim 10 which shifts.
The two or more blocks are divided into groups,
The radiation image detection apparatus according to claim 11, wherein the control unit shifts the timing of switching the supply state of the power for each group.
The radiation image detecting apparatus according to claim 12, wherein at least one block is disposed between two blocks belonging to the same group.
The radiation image detection apparatus according to claim 11, wherein the control unit shifts the timing of switching the supply state of all the power of the two or more blocks.
The control unit causes at least one of the blocks including the multiplexer to which the partial charge amplifier is not connected among the plurality of blocks to always be in the second state during the irradiation start detection operation. The radiographic image detection apparatus of any one of Claims 10 thru | or 14.
The radiation image detecting apparatus according to any one of claims 10 to 15, wherein the block is provided for each area configured by pixels connected to a plurality of adjacent signal lines.
17. The radiation image detecting apparatus according to claim 16, wherein a plurality of adjacent ones of the blocks that are respectively responsible for the adjacent areas are mounted on the same chip, and a plurality of the chips are provided.
The radiation image detection apparatus according to claim 17, wherein the control unit switches the supply state of the power of the block in units of the block in charge of the area or in units of the chip.
The radiation image detection apparatus according to any one of claims 1 to 18, wherein the detection pixel is a dedicated pixel specialized for the irradiation start detection operation.
20. The temperature drift correction unit according to claim 10, further comprising: a temperature drift correction unit that corrects a temperature drift of the digital signal caused by a temperature distribution deviation generated in the signal processing circuit due to switching the power supply state of the block. The radiographic image detection apparatus of any one term.
The radiation image detection according to any one of claims 1 to 20, wherein the sensor panel and the signal processing circuit are electronic cassettes housed in a portable case and fed from a battery mounted in the case. apparatus.
A sensor panel in which pixels which are irradiated from the radiation generating apparatus and sensitive to the radiation transmitted through the subject and store charges are arranged in a two-dimensional manner, and a plurality of signal lines for reading out the charges are arranged; A signal processing circuit that performs signal processing by reading an analog voltage signal according to the charge from a pixel, and a plurality of charge amplifiers included in the signal processing circuit, provided for each of the signal lines, and the signal line A plurality of charge amplifiers connected to one end of the plurality of charge amplifiers for converting the charges from the pixels into voltage signals of the analog, and a multiplexer included in the signal processing circuit, having a plurality of input terminals; A charge amplifier is connected to each of the plurality of input terminals, and sequentially selects and outputs the analog voltage signal from the plurality of charge amplifiers. And an AD converter included in the signal processing circuit, which is connected to the subsequent stage of the multiplexer and converts the analog voltage signal output from the multiplexer into a digital signal according to the voltage value In an operation method of a radiation image detection apparatus comprising: an AD converter for performing
Before the start of the radiation irradiation, the charge is read out through the detection channel which is the signal line connected to the detection pixel preset among the pixels, and the digital signal corresponding to the read charge is read out. An irradiation start detection step of executing an irradiation start detection operation of detecting the irradiation start of the radiation;
After the start of the radiation irradiation, a pixel charge accumulation period for accumulating the charge in the pixel elapses, and then the charge is read from the pixel through the signal line, and the digital signal corresponding to the read charge is represented And an image reading step of executing an image reading operation of outputting a radiation image to be provided for diagnosis.
In the irradiation start detection step, among the plurality of charge amplifiers connected to the multiplexer, the analog signals from some of the charge amplifiers including the detection charge amplifier that is the charge amplifier connected to the detection channel Selectively output a voltage signal to the AD converter;
Allowing the AD converter to execute only the AD conversion process to the selectively output analog voltage signal,
Furthermore, the number of pulses per unit time of the clock signal that defines the operation timing of the AD converter is reduced compared to when reading out the image,
Furthermore, in the irradiation start detection operation, when the power supplied to the charge amplifier at the time of the image reading operation is a normal power, at least one of the partial charge amplifiers is lower than the normal power, And a method of operating a radiation image detection apparatus driven in a low power state where power greater than 0 is supplied.